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UOIL  /\IVIiVlWINi/\   PI  1 


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1 1 06  R.  E.  TRUST  BUILDING 
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EGGS  IN  COLD  STORAGE 


THEORY  AND  PRACTICE  IN  PRESERVING  EGGS  BY  RE- 
FRIGERATION.   DATA,  EXPERIMENTS,  HINTS  ON 
,     CONSTRUCTION,  ETC.,  FROM    PRACTICAL 
EXPERIENCE,  WITH  ILLUSTRATIONS. 


BY 


MADISON    COOPER. 


CHICAGO  : 
H.  S.  RICH   &   CO. 

1899. 


«£ 


Copyrighted  1898,  IX1)') 
BY  MADISON  COOPER. 


PKKSS  OK 

ICK  AND  RKFRIOIOK  \  riox. 

CHICAGO. 


PREFACE. 

IN  the  interest  of  a  better  understanding1  and  dissem- 
ination of  knowledge  on  the  cold  storage  of  eggs, 
the  writer  has  communicated  with  quite  a  large  num- 
ber of  individuals  and  companies,  asking  their  ideas 
and  requesting  that  they  give  full  answers  to  a  printed 
list  of  questions  sent  them.  Although,  at  first,  the 
replies  were  rather  slow  in  coming  in,  the  total  result 
of  these  letters  has  been  most  gratifying;  nearly  one- 
half  acknowledging  receipt  of  the  inquiry,  and  more 
than  one-half  of  this  number  giving  fairly  full  replies 
to  the  questions  submitted.  Considering  the  fact 
that  the  inquiries  were  regarded  by  some  as  being  of 
a  rather  personal  nature,  the  proportion  of  managers 
sending  full  replies  is  large.  Several  gentlemen  were 
frank  enough  to  say  that  personal  considerations  pre- 
vented them  from  giving  any  information;  others 
gave  guarded  or  partial  replies.  In  the  main,  how- 
ever, storage  men  have  been  willing  to  give  informa- 
tion and  exchange  ideas. 

The  list  of  inquiries  sent  out  covers  the  subject 
very  thoroughly,  and  divides  it  into  six  different 
parts,  with  three  separate  questions  relating  to  each. 
To  the  data  so  cheerfully  furnished  by  others  is  added 
information  from  thewriter's  experience  and  practice, 
with  such  explanation  of  theory  and  practice  as  may 
seem  necessary  to  a  clear  understanding  of  the  prin- 
ciples of  successful  egg  refrigeration.  It  is  hoped 
that  those  who  are  new  to  the  business  may  obtain 
valuable  information  from  these  collected  data,  and 
that  those  with  experience  may  derive  some  benefit 
in  the  way  of  a  review,  and  possibly  pick  up  some 
new  ideas  as  well. 

A  large  portion  of  the  matter  contained  in  these 


Q  C U  fi  x  - 


4  PREFACE. 

pages  appeared  in  Ice  and  Refrigeration  as  a  series 
of  articles  entitled:  "Eggs  in  Cold  Storage."  The 
present  book  is  printed  for  the  purpose  of  putting 
the  matter  in  permanent  form,  believing  that  those 
who  have  followed  the  original  articles  would  find  it 
convenient  for  future  reference.  While  the  present 
book  has  many  shortcomings,  and  there  is  no  doubt 
room  for  the  addition  of  much  information,  reliable 
data,  and  the  results  of  extended  observations  and 
tests,  there  has  not  heretofore  been  anything  like  a 
complete  write-up  of  the  subject;  and  in  consideration 
of  this  fact  the  reader  is  asked  to  be  liberal  in  his 
criticism. 

If  any  errors  or  lack  of  details  are  noted,  the 
author  would  gladly  acknowledge  and  explain  the 
points  at  fault  if  his  attention  is  called  toany.  No  other 
object  has  been  in  mind  in  writing  these  articles  than 
a  furtherance  of  scientific  knowledge  on  the  subject 
of  refrigeration  as  applied  to  the  preservation  of  per- 
ishable products,  and  the  great  assistance  rendered 
by  those  who  have  written  painstaking  replies  to  the 
list  of  inquiries  is  hereby  acknowledged.  The  com- 
bination and  comparison  of  information  are  beneficial, 
and  if  those  who  have  further  data  or  records  of  tests 
will  only  put  them  before  others  in  their  line  of  busi- 
ness, no  loss  will  be  sustained  by  the  individual  giv- 
ing the  information,  while  much  general  good  will 
result. 


INTRODUCTION. 

THE  value  of  the  eggs  placed  in  cold  storage  for 
preservation  is  estimated  at  about  $20,000,000 
annually  for  the  United  States  alone.  Considering 
the  importance  the  industry  has  already  attained,  its 
rapid  growth  and  future  outlook,  the  amount  of  ac- 
curate information  available  to  those  engaged  in  the 
business  seems  very  meager.  The  difficulties  to  be 
overcome,  the  skill  required. and  the  importance  of  a 
well  designed  structure  are  not  usually  explained  by 
those  interested  in  promoting  new  enterprises  in  this 
line,  and  consequently  not  appreciated  by  those  mak- 
ing the  investment.  Financial  disaster  has  over- 
taken many  large  companies  who  have  erected  costly 
refrigeratingwarehouses;  thosewhich  have  succeeded 
have  been  forced  to  install  new  systems,  make  expens- 
ive changes,  and  make  a  thorough  study  of  the  prod- 
ucts handled.  The  experience  of  nearly  all  has  been 
emphasized  at  times  by  heavy  losses  paid  in  claims 
made  by  customers  for  damage  to  goods  while  in 
storage,  or  the  necessity  of  running  a  large  house 
while  doing  a  very  small  business.  Those  about  to 
become  interested  in  the  business  may  find  food  for 
thought  in  the  above,  and  the  history  of  a  dozen 
houses,  in  diiferent  localities, will  be  good  information 
for  would-be  investors. 

The  scarcity  of  knowledge  on  the  subject  in  hand, 
while  being  partly  the  result  of  the  half  developed 
state  of  the  art  until  very  recently,  is  also  very 
largely  owing  to  narrow-mindedness  on  the  part  of 
some  of  the  older  members  of  the  craft,  who  have 
largely  obtained  their  skill  by  years  of  experience 
and  study,  some  of  them  having  expended  large  sums 
on  experimental  work.  The  same  experiments  have 


6  INTRODUCTION. 

perhaps  been  made  before,  and  are  of  necessity  to 
be  made  again  by  others,  simply  because  the  first 
experimenter  would  not  give  other  people  the  benefit 
of  his  experience.  It  seems  at  this  stage  in  the  de- 
velopment of  refrigeration,  that  the  improvements  to 
be  made  during-  the  next  twenty  years  will  be  of  very 
much  less  importance  than  those  made  during-  the 
twenty  years  just  ending-;  trade  secrets,  so  jeal- 
ously guarded  by  some,  must  disappear,  as  they  have 
in  other  branches  of  engineering-.  Storag-e  men  have 
been  oblig-ed  to  work  out  their  own  salvation  in  stor- 
ing- problems,  sometimes  sending  their  most  difficult 
points  to  be  answered  through  the  columns  of  Ice  and 
Refrigeration,  and,  perhaps,  comparing  ideas  with 
those  of  their  personal  friends  in  the  same  line  of 
business.  It  is  to  be  observed  that  the  most  pro- 
gressive and  up-to-date  manufacturing  concerns  in 
the  United  States  to-day  are  giving  their  contempo- 
raries every  opportunity  of  observing  their  methods, 
and  are  very  willing  and  anxious  to  talk  over  matters 
pertaining  to  their  work,  from  an  unselfish  stand- 
point. So,  too,  the  successful  cold  storage  of  the 
future  will  be  sure  to  make  "  visitors  welcome." 

In  anything  which  will  appear  in  these  articles,  it 
is  not  the  writer's  intention  to  convey  the  idea  that 
any  mere  theoretical  knowledge,  which  can  be  ac- 
quired by  reading  and  study,  or  even  by  an  exchange 
of  ideas  in  conversation,  can  take  the  place  of  practi- 
cal observation  in  actual  house  management;  but 
there  are  applications  of  well  known  natural  laws, 
which  are  not  generally  understood  by  storage  men, 
and  their  progress  is  handicapped  from  lack  of  this 
theoretical  knowledge.  The  two  following  illustra- 
tions, bearing  on  temperature  and  ventilation,  are 
among  the  common  errors  made  in  practice,  yet  easily 
understood  when  studied  and  tested:  Some  storage 
houses  have  formerly  held  their  egg  rooms  at  33°  F., 
fearing  any  nearer  approach  to  the  freezing  point  of 


INTRODUCTION.  7 

water  (32°  F.),  thinking-  the  eggs  would  freeze.  A 
simple  experiment  would  settle  this  point,  giving  the 
exact  freezing-  temperature,  as  well  as  the  effect  of 
any  low  temperature  on  the  egg  tissues.  Again, 
others  have  thought  to  ventilate  by  opening-  doors 
during-  warm  weather.  It  never  happens  that  storag-e 
rooms  can  be  benefited  by  this  treatment  at  any  time 
during-  the  summer  months,  and  only  occasionally 
during*  spring-  and  fall.  The  dew  point  of  outside  air 
is  rarely  below  45°  F.  during-  summer,  and  when 
cooled  to  the  temperature  of  an  eg-g-  room,  moisture 
will  be  deposited  on  the  goods  in  storage,  causing-  a 
vigorous  -growth  of  mildew. 


EGGS  IN  COLD  STORAGE. 


CHAPTER  I. 

TEMPERATURE. 

TEMPERATURE  is  selected  for  first  considera- Temperature 
.     .        .  .,  ,,        ,.    .  .          more  important 

tion,  as  it  is  the  primary  elementoi  reingeration,  than  any  other 

Jf  -,.,.  ^  A  condition. 

and  more  important  than  any  other  condition.  Correct 
temperature  alone,  however,  will  not  produce  success- 
ful results,  anymore  than  a g-ood  air  circulation,  or  cor- 
rect ventilation,  would  give  good  results  with  a  wrong- 
temperature.  This  applies  more  especially  to  egg  re- 
frigeration, someproducts  requiringonlyalowtemper- 
ature  for  preservation.  The  common  impression  of 
cold  storage  is  what  the  name  implies — simply  a  build- 
ing in  which  the  rooms  may  be  cooled  to  a  low  degree 
as  compared  with  the  outside  air.  Even  those  who 
build,  sell  and  erect  refrigerating  machinery  and  appa- 
ratus often  show  either  gross  carelessness  or  ignor- 
ance of  the  requirements  of  a  house  which  will  produce 
successful  results.  After  a  careful  examination  of 
some  of  the  recently  constructed  houses,  supposed  to 
be  strictly  modern  and  up  to  date,  the  writer  gets  the 
impression  that  the  architects  regard  temperature 
as  the  only  requisite  for  perfect  work.  Some  of  the  unskiiifuiiy 
rooms  in  these  new  houses  are  simply  insulated  and  e^j?  m?ms. 
fitted  with  brine  or  ammonia  pipes,  the  location  of  the 
coils  having  no  attention  whatever,  being  placed,  in 
most  cases,  in  convenient  proximity  to  the  pipe  main, 
and  in  one  or  two  instances,  the  top  pipe  of  the  cooling- 
coils  was  fully  two  feet  from  the  ceiling.  The  ne- 
cessity of  providing  for  air  circulation  seemed  not 
worthy  of  consideration,  to  say  nothing  of  the  lack  of 
anything  like  an  efficient  ventilating  system. 

Questions  regarding  the  correct  temperature  of  Opinions 
egg  rooms  have   been   asked    repeatedly  of  storage  correct'"* 

,       -  •       j.i        «          •          '      i  i  temperature. 

men  who  have  been  in  the  business  long  enough  to  be 


10  EGGS   IN    COLD    STORAGE. 

looked  to  for  advice,  the  same  person,  perhaps, 
giving-  a  different  answer,  from  time  to  time,  as  his 
ideas  changed.  The  query  has  also  been  asked  and 
answered  through  the  columns  of  ICE  AND  REFRIG- 
ERATION a  number  of  times.  At  present,  however, 
there  is  no  temperature  on  which  a  large  majority  of 
persons  can  agree  as  being-  rig-ht,  and  as  giving-  su- 
perior results  to  any  other.  The  claims  made  by  the 
advocates  of  different  temperatures  will  be  consid- 
ered, to  determine,  if  possible,  what  degree  is  giving 
the  best  results  in  actual  practice. 

The  three  questions  relating  to  temperature  were 
temperature.  written  to  draw  out  opinion  as  to  the  right  tempera- 
ture, the  lowest  safe  temperature,  and  what  delete- 
rious effect,  if  any,  the  egg  sustained  at  low  tempera- 
tures, which  did  not  actually  congeal  the  egg  meat. 
The  three  temperature  queries  were: 

First. — At  what    temperature   do  you   hold   your 
rooms  for  long  period  egg  storage? 

Second- — What  temperature  do  you  regard  as  the 
lowest  limit  at  which  eggs  may  be  safely  stored? 

Third. — What  effect  have  you  noticed  on  eggs  held 
at  a  lower  temperature? 
Fig-ures  All  the  replies  received  contained  answers  relative 

received  relat- 

to  temperature,  and  by  a  very  small  majority  32°  F. 
is  the  favorite  temperature  for  long  period  egg 
storage.  Some  few,  33°  F.  and  34°  F.,  with  a  few 
scattering  ones  up  to  40°  F..  Under  the  freezing 
point,  none  recommended  a  temperature  lower  than 
28°  F.,  and  for  a  very  obvious  reason,  this  being  near 
to  the  actual  freezing  temperature  of  the  albumen  of 
a  fresh  egg.  A  very  respectable  minority  say  a  tem- 
perature ranging  from  30°  F.  to  31°  F.  is  giving  them 
prime  results;  and  several  recommend  30°  F.  straight, 
and  say  they  should  go  no  lower.  In  recent  years 
there  has  been  a  decided  tendency  among  storage 
men  to  get  the  temperature  down  near  the  safety 
limit,  but  many  houses  are  so  poorly  equipped  that 


EGGS  IN    COLD   STORAGE.  11 

they  are  unable  to  maintain  a  uniform  low  tempera- 
ture below  33°  F.,  without  danger  of. freezing-  eggs 
where  they  are  exposed  to  the  flow  of  cold  air  from 
coils.  A  house  must  be  nicely  equipped  to  maintain 
low  temperatures  with  safety.  More  houses  would 
use  temperatures  under  32°  F.,  were  they  able  to, 
without  danger  to  the  eg-g-s.  A  very  successful  east- 
ern  house  issued  a  pamphlet  in  1892.  At  that  time 
they  maintained  a  temperature  of  32°  F.  to  34°  F.  in 
their  rooms.  In  sending-  out  this  little  book  during 
the  winter  of  1897-98  a  postscript  was  added,  as  fol- 
lows: "  This  pamphlet  was  published  in  1892,  when 
our  plant  was  started.  Since  that  time  all  first- 
class  cold  storag-e  houses  have  lowered  their  temper- 
atures materially."  No  better  illustration  than  this 
can  be  cited  to  show  the  tendency  of  the  times. 
These  people  now  use  a  temperature  of  30°  F.  for 
eg-g-s. 

Most  of  the  replies  received  contained  answers  toRePliesto 

query  No.  2. 

question  No.  2,  and  the  greater  portion  state  this  as 
being-  about  2°  F.  lower  than  that  recommended  for 
long-  period  storag-e.  It  is  presumed  that  these  two 
degrees  are  allowed  as  leeway,  or  margin  of  safety, 
for  temperature  fluctuations.  Some  state  that  eg-g-s 
cannot  be  safely  held  below  32°  F.,  but  give  no  reason 
why,  while  two  or  three  say  a  temperature  of  27°  F. 
will  do  no  harm  to  eg-g-s  in  cases.  One  reply  states 
that  egg's  held  in  cut  straw  at  25°  F.  for  three  months 
showed  no  bad  symptoms.  It  has  never  been  made 
clear  how  the  package  can  be  any  protection  against 
temperature,  when  the  temperature  has  been  contin- 
uously maintained  for  a  length  of  time  sufficient  to 
allow  the  heat  to  escape;  and  we  know  that  eggs  will 
positively  freeze  at  25°  F.,  as  proven  by  experiments 
mentioned  in  another  paragraph. 

The  answers  to  question  No.  3  were  few  in  num-  Replies  to 

.  .,  __...  .  ,    1  query  No.  3. 

ber,  but  cover  a  wide  range.  The  scarcity  of  data  on 
this  point  indicates  that  few  have  experimented  with 


12  EGGS   IN   COLD    STORAGE. 

eggs  at  temperatures  ranging-  from  25°  F.  to  30°  F. 
Some  say:  "Dark  spot,  denoting  germ  killed";  others, 
"white  gets  thin";  others,  "eggs  will  decay  more 
quickly";  or,  "they  wnl  not  'stand  up'  as  long  when 
removed  from  storage."  It  is  also  claimed  that  "yolk 
is  hardened  or  'cooked' when  temperature  goes  below 
32°  F."  Some  answers  state  a  liability  of  freezing  if 
eggs  are  held  in  storage  at  a  temperature  below  32C  F, 
for  any  length  of  time. 

As  far  as  possible,  we  will  dig  out  reasons  for  the 
temp£atureBW  c^aims  made  by  advocates  of  both  high  and  low  tem- 
peratures, both  having  equal  consideration.  Taking 
29°  F.  or  30°  F.  and  38°  F.  or  40°  F.,  as  representing 
the  lowest  and  highest  of  general  practice,  we  will  see 
what  is  claimed  by  each ;  and  also  the  faults  of  the 
other  fellow's  way  of  doing  it,  as  they  see  it.  Those 
who  are  holding  their  egg  rooms  at  40°  F.  say  it  is 
economical,  that  the  eggs  keep  well,  that  the  consis- 
tency of  the  egg  meat  is  more  nearly  like  that  of  a 
fresh  egg  after  being  in  storage  six  months,  than  if 
held  at  a  lower  temperature.  As  against  a  low  tem- 
perature they  say:  A  temperature  of  30°  F.  is  expen- 
sive to  maintain;  the  yolk  of  the  egg  becomes  hard 
and  the  white  thin,  after  being  in  store  for  a  long 
hold;  and  that  when  the  eggs  are  taken  from  storage 
in  warm  weather  it  will  require  a  longer  time  to  get 
through  the  sweat  than  if  held  in  storage  at  a  some- 
what higher  temperature,  resulting  in  more  harm  to 
the  eggs.  Some  claim  that  the  keeping  qualities  are 
impaired  by  holding  at  a  temperature  as  low  as  30C  F.,. 
and  others  note  a  dark  spot,  or  clot,  which  forms  in 
the  vicinity  of  the  germ,  when  eggs  are  held  below 
33°  F.  Against  this  formidable  array  of  claims,  the 
low  temperature  men  have  some  equally  strong 
ones,  although  fewer  in  number.  They  say:  There 
is  very  much  less  mildew,  or  must,  at  30°  F.  than  at 
temperatures  above  32°  F.;  the  amount  of  shrinkage 
or  evaporation  from  the  egg  is  less;  an  egg  can  be 


EGGS   IN   COLD   STORAGK.  13 

held  sweet  and  reasonably  full  at  this  temperature 
from  six  to  eight  months.  This  last  claim  is  a  broad 
one,  and  very  few  houses  are  turning-  out  eggs  an- 
swering to  this  description. 

The  following,  relating  to  high  temperatures,  is 
quoted  from  a  letter  written  by  one  of  the  best  posted  Je 
men  in  the  business,  who  has  spent  much  money  and 
time  on  experiments,  and  studied  the  question  for 
years.  He  says:  "A  temperature  of  40°  F.  is  very 
good  for  three  months' holding,  but  if  they  run  over 
that,  it  is  more  than  likely  the  eggs  will  commence  to 
cover  with  a  white  film,  which  grows  the  longer  they 
stand,  and  finally  makes  a  musty  egg."  This  gen- 
tleman advocates  a  temperature  of  30°  F.  for  long 
period  holding.  It  should  be  noted  that  the  high 
temperature  men  ignore  entirely  the  effect  of  high 
temperatures  on  the  growth  of  this  fungus,  spoken  of 
above  as  a  white  film.  The  worst  £hing  about  most 
storage  eggs  is  the  taste  caused  by  this  growth, 
(usually  called  mildew  or  mold),  which  results  in  what 
is  commonly  called  a  musty  egg.  To  enable  us  to 
understand  the  validity  of  these  claims  made  by  the 
30°  F.  people,  it  will  be  necessary  for  us  to  ascertain 
the  conditions  which  are  favorable,  and  also  the  con- 
ditions which  are  unfavorable  for  the  propagation  of 
this  growth  of  fungus,  which  has  given  storage  men 
so  much  trouble,  ever  since  cold  storage  was  first 
used  for  the  preservation  of  eggs. 

Heat  and  moisture  are  the  two  conditions  lead  ing-  Causes  operat- 

&  ing-  to  produce 

to  its  rank  growth,  and  the  opposite — dry  ness  and  cold  [JI8rrow1JJ1of    s 
— will  retard  or  stop  the  growth  entirely.     In  moist,  in oM  storage, 
tropical  countries  many  species  of  this  parasite  grow, 
while  in  the  cold,  dry  regions  of  the  north  its  exist- 
ence is  limited  to  a  single  variety.     The  causes  lead- 
ing to  a  growth  of  the  fungus  on  the  outside  of  an  egg 
are  not  far  to  seek.     It  feeds  on  the    moisture  and 
products  of  decomposition  which  are  being  constantly 
given  off  by  an  egg,  from  the  time  it  is  first  dropped 


14  EGGS'  IN    COLD   STORAGE. 

until  its  disintegration,  unless  immersed  in  a  liquid, 
or  otherwise  sealed  from  contact  with  the  air.  This 
evaporation  not  only  takes  moisture  from  the  egg, 
but  carries  with  it  the  putrid  elements  from  the  egg 
tissue,  resulting-  from  a  partial  decomposition  of  the 
outer  surface  of  the  eg-g-  meat.  Conditions  of  excess- 
ive moisture  and  the  presence  of  decaying-  animal  or 
vegetable  matter,  tog-ether  with  a  moderate  degree  of 
heat,  are  essential  to  the  formation  of  fungus  of  the 
species  which  are  found  growing-  on  eg-g-s  in  cold 
storage.  As  the  heat  and  moisture  are  increased,  the 
growth  of  fungus  will  be  proportionate.  Furthermore, 
we  all  understand  that  heat  hastens  decomposition, 
and  the  partial  decomposition  of  an  egg  results  in  a 
growth  of  the  fungus,  as  before  explained,  when  con- 
ditions of  temperature  and  humidity  are  favorable.  If 
the  temperature  is  low,  this  growth  is  slow;  for  in- 
stance, if  eggs  are  held  at  a  temperature  of  30°  F.  in 
an  atmosphere  of  given  humidity,  the  growth  of  fungus 
is  less  rapid  than  if  held  at  any  temperature  higher, 
with  the  same  per  cent  of  humidity.  As  our  subject 
merges  into  humidity  here,  the  reader  is  referred  to 
what  is  said  under  this  head  in  another  chapter, 
someexperi-  Returning  to  the  objections  urged  against  low 

™<Skngnpoint  temperatures,  we  will  see  what  damage  is  claimed 
from  the  use  of  a  temperature  of  29°  to  30°  F.  The 
objections  are:  Liability  of  freezing;  germ  is  killed; 
white  becomes  thin;  yolk  is  hardened,  and  eggs  will 
not  keep  as  long  when  removed  from  storage.  Some 
interesting  results  are  obtained  from  experiments 
made  by  the  writer.  Half-rotten  or  "sour"  eggs 
freeze  at  temperatures  just  a  trifle  under  32°  F. 
Fresh  eggs  freeze  at  26°  to  27°  F.  In  testing  eggs 
which  had  been  held  in  storage  for  several  months,  it 
was  noted  that  the  freezing  point  had  been  depressed 
from  1°  to  2°  F.  An  egg  which  is  leaky  will  freeze  at 
2°  to  3°  higher  temperature  than  one  which  is  sound, 
probably  owing  to  the  evaporation  resulting  in  a  lower 


EGGS    IN   COLD   STORAGE.  15 

temperature.  The  freezing  point  of  eggs,  as  above, 
is  understood  as  being  the  degree  at  which  they  begin 
to  form  ice  crystals  inside.  Of  the  replies  received 
touching  on  the  freezing  point  of  eggs,  nearly  all  agree 
with  above  experiments.  The  "  dead  germ  "  theory  Dead  germ 
the  writer  has  never  been  able  to  locate  in  fact,  hav- 
ing never  seen  anything  of  the  kind  in  eggs  held  as 
low  as  28°  to  29°  F.  for  several  weeks'  time;  nor  in 
eggs  held  at  30°  F.,  or  a  trifle  under,  through  the  sea- 
son. As  only  two  or  three  mention  having  noted  this 
result,  it  would  seem  that  some  local  conditions,  and 
not  low  temperature,  were  responsible. 

The  matter  of  the  white  becoming  thin  when  eggs 
are  held  at  low  temperatures  has  some  bearing;  in 
fact,  any  egg  held  at  a  cold  storage  temperature  for 
a  long  carry  will  show  this  fault,  to  a  certain  extent, 
especially  if  cooled  quickly  when  stored,  or  warmed 
suddenly  when  removed  from  storage.  With  refer- 
ence to  the  above,  it  is  the  writer's  opinion  that  a  dif- 
ference of  4°  to  6°  F.  in  carrying  temperature  will 
not  be  noticeable  in  its  effect  on  the  albumen  of  an 
egg;  and  as  to  the  effect  of  a  low  temperature 
on  the  egg  yolk,  it  has  been  demonstrated  that 
any  temperature,  which  will  not  actually  congeal  the 
albumen,  will  not  harm  the  yolk  of  an  egg.  There 
is  a  slight  tendency,  in  this  case,  to  a  similar  effect  to 
that  produced  by  a  low  temperature  on  cheese;  that 
is,  causes  it  to  become  "  short  "  or  crumbly. 

In  regard  to  a  low  temperature  egg  not  keeping  as 
long  when  removed  from  storage,  it  has  been  the 
experience  of  the  writer  that  no  difference  was  noted 
between  eggs  put  out  from  storage  and  the  current 
receipts  of  fresh  eggs,  so  far  as  any  complaint  or 
objection  was  concerned,  the  eggs  being  shipped  in 
all  directions,  in  all  weathers  and  subject  to  many 
different  conditions.  A  test  was  also  made,  by  placing  A  test  showing 

,,  ..  r  i'iii,  ....  keeping- quali- 

three  dozen  of  eggs,  which  had  been  carried  m  storage  ties  of  eggs 

at  a  temperature  of  28°  F.  to  30°  F.  for  five  months,  temperature. 


16 


EGGS    IN   COLD    STORAGE. 


in  a  case  along-  with  three  dozen  fresh  eggs.  After 
three  weeks  no  pronounced  change  was  noted  in 
either,  both  showing-  considerable  evaporation  as  a 
result  of  exposure  to  the  dry  fall  atmosphere.  They 
were  exposed  to  the  temperature  of  the  receiving- 
room,  fluctuating-  from  50°  F.  to  80°  F.  The  eg-g-s 
from  storage  went  throug-h  a  "sweat,"  while  the  fresh 
were  not  subjected  to  any  such  trial.  As  most  eggs 
are  consumed  inside  of  three  weeks  after  being  re- 
moved from  storage,  this  would  seem  like  a  good 
practical  test  of  the  vitality  of  a  low  temperature 
egg.  A  mere  matter  of  economy  between  holding  a 
room  at  40°  F.  and  30°  F.,  while  readily  appreciated 
and  admitted,  seems  of  very  small  importance,  when 
a  positive  advantage  can  be  obtained  by  carrying  eggs 
at  the  lower  temperature;  and  a  difference  of  4°  F.  to 
5°  F.  would  be  scarcely  worth  considering. 

ui°re  fc  relents"  ^n  a(l  vantage  °f  l°w  temperature,  not  yet  men- 
"spot"  rotten  tioned,  is  the  increased  stiffness,  or  thickness,  of  the 
white  of  the  egg  while  in  storage,  holding  the  yolk  in 
more  perfect  suspension.  When  eggs  are  held  at  a 
temperature  of  36°  F.,  or  above,  for  any  period  longer 
than  four  months,  the  yolk  has  a  decided  tendency  to 
rise  and  stick  to  the  shell,  causing  rotten  eggs,  known 
as  "spots."  It  is  usually  understood  that  the  yolk  set- 
tles; but,  being  of  a  fatty  composition,  it  is  lighter  than 
the  albumen,  and  rises  instead.  If  the  albumen  is 
maintained  in  a  heavy  consistency,  the  yolk  is  retarded 
from  rising,  and  held  in  a  more  central  position.  It 
was  long  a  practice  with  storage  men  to  turn  eggs  at 
least  once  during  the  season,  to  prevent  the  above 
trouble,  and  some  recommend  it  even  now;  but  the 
practice  has  been  generally  abandoned  with  the  ad- 
vent of  low  temperatures  for  egg  storing. 

When  eggs  are  put  in  cold  storage  they  should  not 
be  cooled  rapidly.  The  effect  on  the  egg  tissues  is 
bad  —  they  should  have  time  to  rearrange  themselves 
to  the  changed  temperature.  This  is  especially  true 


from  storage, 


EGGS    IN   COLD   STORAGE.  17 

where  egg's  are  placed  in  storage  in  extreme  warm 
weather.  Sudden  warming  is  also  detrimental  to  the 
welfare  of  an  egg,  for  a  similar  reason  to  above.  The 
most  noticeable  effect  of  either  is  a  thinned  albumen. 
If  this  process  of  cooling  and  warming  could  be  prac- 
ticed carefully  (which  is  not  always  practicable  com- 
mercially), a  well  kept  storage  egg  would' come  out  of 
storage  with  nearly  the  same  vitality  it  had  when  fresh. 


Data  available 
on  humidity 
practically 
nothing-. 


Evaporation 
and  mold  can 
be  prevented. 


Questions 
relating-  to 
humidity. 


CHAPTER  II. 

HUMIDITY. 

INFORMATION  on  the  subject  of  humidity,  as 
J.  applied  to  the  cold  storage  of  eggs,  is  very  meager. 
Not  more  than  a  dozen  of  the  replies  received  in 
answer  to  the  li&  t  of  inquiries  sent  out  contain  infor- 
mation on  the  three  queries  under  the  head  of  hu- 
midity. Considering  the  amount  of  talk  we  have  all 
heard,  with  dry  air  as  a  subject,  this  scarcity  of  knowl- 
edge is  rather  surprising.  Those  who  have  had  ex- 
perience with  cold  storage  work  and  the  products 
handled  are  well  aware  that  an  essential  for  good  re- 
sults in  egg  refrigeration  is  a  dry  atmosphere  in  the 
egg  room ;  but  just  how  dry,  very  few  are  able  to  give 
even  an  approximate  estimate.  Very  likely  if  a  cold 
storage  man  is  asked  in  regard  to  it,  he  will  reply 
that  an  egg  room  should  be  "neither  too  moist  nor 
too  dry."  What  this  "happy  medium  "  is,  that  will 
not  shrink  or  evaporate  the  eggs  badly,  and  yet  keep 
down  the  growth  of  fungus  to  a  minimum,  is  what  all 
are  striving  for,  and  very  few  have  the  means  of 
knowing  when  this  point  is  reached.  A  few  years 
ago  a  prominent  commission  man,  in  conversation 
with  the  writer,  speaking  of  storage  eggs,  said : 
"You  storage  men  are  between  the  devil  and  the 
deep  sea.  You  always  shrink  'em  or  stink  'em"; 
meaning  that  eggs  which"  were  held  long  in  storage 
would  show  either  a  considerable  evaporation  or  a 
radical  "  musty  "  flavor.  To  some  extent  this  is  true, 
but  with  a  penetrat-ing  circulation,  careful  ventilation 
and  a  judicious  use  of  absorbents  (all  of  which  will 
be  considered  under  their  proper  heads)  egg  can  be, 
and  are,  turned  out  of  storage  without  this  strong, 
foreign  flavor,  and  with  little  evaporation  or  shrinkage. 
The  questions  relating  to  humidity  were  written 
with  a  full  understanding  of  the  scarcity  of  informa- 
tion on  the  subject,  and  were  designed  to  locate,  if 

18 


EGGS    IN   COLD   STORAGE.  19 

possible,  those  who  were  making*  tests  of  air  moist- 
ure, and  get  opinions  on  the  correct  humidity  for  a 
given  temperature.  The  following- are  the  queries: 

First. — What  tests,  if  any,  have  you  made  of  the 
dryness  or  humidity  of  your  egg  rooms? 

Second. — What  per  cent  of  air  moisture  do  you  find 
gives  the  best  results  at  the  temperature  you  use? 

Third. — What  instrument  do  you  use  for  testing 
air  moisture? 

Questions  1  and  3  are  practically  the  same,  the 
latter  being  written  simply  to  make  the  query  more 
plain  and  indicate  whether  an  instrument  or  some 
other  test  was  used  for  determining  air  moisture. 
Four  houses  reporting  are  using  the  dry  and  wet  bulb 
thermometers;  the  others  are  using  hygrometers  of 
French  or  German  make. 

The  answers  to  question  2  vary  greatly  ;  some 
also  giving  the  actual  testing  humidity  of  their  rooms  humidity. 
and  their  opinion  of  a  correct  degree  as  well.  From 
70  to  80  per  cent  of  humidity  is  the  test  of  nearly  all 
reporting,  and  of  the  rooms  tested  by  the  writer, 
nearly  all  show  a  similar  humidity,  with  one  occasion- 
ally going  as  high  as  85  per  cent,  and  some  as  low  as 
65  per  cent.  Two  answers  recommend  a  humidity 
of  65  per  cent,  and  one  a  humidity  of  60  per  cent, 
with  a  temperature  of  30°  F.  to  32°  F.  Others  hold 
that  their  testing  humidity  of  70  to  80  per  cent  is 
correct.  The  matter  of  correct  humidity  will  be  dis- 
cussed further  on. 

The  humidity  of  a  room  depends  on  the  season 
a  moderate  extent,  and  the  condition  of  the  room,  as  humidity. 
regards   ventilation,  in  some   cases.     In  late  fall  or 
winter,  especially,  if   air  is   taken   directly  into  the 
room  from  the  outside,  the  humidity  will  be  low.     As 
cool  weather    approaches,   the   tendency   is  for  the 
humidity  to  rise,  and  unless  kept  down  by  ventilation 
or  by  the  use  of  absorbents,  serious  consequences  are 
sure  to  follow. 


20 


EGGS    IN    COLD   STORAGE. 


what  relative         To  enable  us  to  thoroughly  understand  the  mean- 
humidity         .  J 
signifies.          mg-  of  relative  humidity,  as  it  is  called,  we  will  study 

a  few  extracts  from  "  Instructions  to  Voluntary  Ob- 
servers," issued  by  the  Weather  Bureau  at  Washing-- 
ton, D.  C.  Humidity  is  considered  on  a  decimal  scale, 
with  100  the  saturation  point  of  the  air,  at  which  it 
will  hold  no  more  water  vapor,  and  0  the  point  at 
which  air  contains  no  moisture  whatever.  The  vari- 
ous percentag-es  between  these  points  is  a  degree  of 
humidity  relative  to  these  two  extremes,  or  relative 
humidity.  The  quotations  below  are  not  contained 
in  the  recent  issue  of  instructions,  but  are  from  the 
issue  of  1892,  which  is  now  superseded  by  that  of  1897. 


Quoted  from 
"Instructions 
to  Weather 
Observers." 


WATER   VAPOR   IN   AIR. 

The  air  contains  vapor  of  water,  transparent  and  color- 
less like  its  other  g-aseous  components.  It  only  becomes  visible 
on  condensing  to  fog"  or  cloud,  which  is  only  water  in  a  fine 
state  of  division.  The  amount  is  very  variable  at  different 
times,  even  in  the  vicinity  of  the  ocean.  The  amount  of  moisture 
that  can  exist  as  vapor  in  the  air  depends  on  the  temperature. 
There  is  a  certain  pressure  of  vapor,  corresponding-  to  every 
temperature,  which  cannot  be  exceeded  ;  beyond  this  there  is 
condensation.  This  temperature  is  called  the  temperature  of 
saturation  for  the  pressure.  When  the  temperature  of  the  air 
diminishes  until  the  saturation  temperature  for  the  vapor  con- 
tained is  reached,  any  further  fall  causes  a  condensation  of 
moisture.  The  temperature  at  which  this  occurs  is  called  the 
dew  point  temperature  of  the  air  at  that  time.  The  less  the 
quantity  of  moisture  the  air  contains,  the  lower  will  be  the 
temperature  of  the  dew  point.  For  different  saturation  temper- 
atures, the  weight  of  vapor,  in  grains,  contained  in  a  cubic 
foot  of  air  is  as  follows: 


Temperature  of 
Saturation,  Degrees  F. 

0 
10 
20 
30 
40 
50 
60 
70 
80 
90 
100 


Weig-ht  in  a 
Cubic  Foot,  Grains. 

0.56 

0.87 

1.32 

1.96 

2.85 

4.08 

5.74 

7.98 
10.93 
14.79 
19.77 


EGGS    IN    COLD   STORAGE.  21 

The  air  is  never  perfectly  saturated,  not  even  when  rain 
is  falling-;  neither  is  it  ever  perfectly  dry  at  any  place.  Rela- 
tive humidity  expresses  relative  amount  of  moisture  in  the  air 
only  as  long  as  the  temperature  of  the  air  remains  constant. 
For  this  reason  relative  humidity  is  an  imperfect  datum.  At  a 
low  temperature,  even  a  high  relative  humidity  represents  a 
very  small  amount  of  vapor  actually  in  the  air,  while  a  low 
relative  humidity  at  a  high  temperature  represents  a  great 
deal. 

The  most  important  law  relating- to  above  concise 
statements,  and  one  which,  if  carefully  noted  and 
applied,  will  make,  all  work  in  humidity  easily  under- 
stood, is  best  expressed  thus:  The  capacity  of  air  for 
moisture  is  increased  with  its  temperature.* 

At  a  temperature  of  40°  F.,  air  will  hold  in  sus- 
pension more  water  vapor  than  at  any  lower  tempera- 
ture (see  table);  and  when  the  difference  is  as  much 
as  10°  F.,  the  difference  in  the  amount  of  moisture 
the  air  will  hold  is  very  considerable.  To  illustrate: 
Air  which  is  saturated  with  moisture  at  30°  F.,  when 
raised  in  temperature  to  40°  F.,  then  holds  but  68  per 
cent  of  its  total  capacity. 

Under  the  head  of   "Temperature,"  it  is  stated  . th 

that:  "If  eggs  are  held  at  a  temperature  of  30°  F.  in 
an  atmosphere  of  a  given  humidity,  the  growth  of 
fungus  is  less  rapid  than  if  held  at  any  temperature 
higher,  with  the  same  per  cent  of  humidity.  Refer- 
ring again  to  the  table,  we  see  that  a  cubic  foot  of  air, 
when  saturated  at  a  temperatureof  40°  F.,contains2. 85 
grainsof  water  vapor,  while  at  30°F.  it  contains  but  1.96 
grains,  or  only  about  two-thirds  as  much  as  at  40°  F. 
The  same  holds  true  with  any  relative  humidity,  the 
same  as  when  the  air  is  saturated.  Take,  for  instance, 
air  at  a  temperature  of  40°  F.,  with  a  humidity  of  75 
per  cent,  then  a  cubic  foot  of  air  holds  2.14  grains  of 
water  vapor  per  cubic  foot;  and  at  a  temperature  of 

*  Strictly  speaking,  air  has  no  capacity  for  moisture,  the  water  vapor  being 
simply  diffused  through  the  air,  after  the  nature  of  a  mechanical  mixture.  For 
all  practical  purpases,  we  may  regard  it  as  being  absorbed  by  the  air,  and  it  is 
usually  so  treated. 


22  EGGS    IN   COLD   STOKAGK. 

30°  F.,  with  the  same  relative  humidity,  it  would  hold 
but  1.47  grains.  This  great  difference  in  the  amount 
of  moisture  contained  in  the  air  at  different  temper- 
atures, and  still  having  the  same  relative  humidity, 
has  as  radical  an  effect  on  the  growth  of  fungus 
as  does  the  difference  in  temperature.  This  is  no 
mere  theory,  as  the  writer  has  demonstrated  it,  to  his 
own  satisfaction,  at  least,  during-  several  seasons' 
observation.  If  it  is  hoped  to  keep  down  the  growth 
of  fungus  in  a  temperature  of  40°  F.  by  maintaining  an 
Result  of  too  atmosphere  with  a  lower  relative  humidity,  the  result 
r<Smanef??  is  a  badly  evaporated  egg,  which  loses  its  vitality  and 
value  very  rapidly  when  held  in  storage  for  a  term 
exceeding  three  or  four  months;  the  white  becomes 
thin  and  watery,  with  a  strong  tendency  to  develop 
"spot"  rotten  eggs.  As  the  fullness  or  absence  of 
evaporation  is  of  only  secondary  consideration  to  their 
sweetness,  when  eggs  are  tested  by  buyers,  it  is 
necessary  to  prevent  this  trouble  if  the  eggs  turned 
out  from  storage  are  to  be  considered  first-class. 
humwitry lnotv&  From  the  foregoing  it  seems  clear  that  to  turn  out 
sweet  eggs  at  a  temperature  of  40°  F.  it  is  necessary 
to  maintain  a  lower  relative  humidity  than  at  any  tem- 
perature lower,  and  the  result  cannot  fail  to  be  as  de- 
scribed. The  writer  has  already  given  a  summary  of 
the  replies  to  the  questions  relating  to  humidity,  which 
are  few  in  number,  and  not  very  complete.  A  little 
is  better  than  nothing,  however,  and  by  comparing 
his  own  data  with  the  results  obtained  by  others,  and 
paying  careful  attention  to  their  opinions,  the  follow- 
ing table  of  correct  humidity  for  a  given  temperature 
in  egg  rooms  has  been  compiled.  There  are  no  data  on 
the  subject  in  print,  so  far  as  known,  and  no  claim  for 
absolute  accuracy  is  made  in  presenting  this  first 
effort  in  that  direction,  but  as  the  figures  are  taken 
from  actual  results,  no  great  mistake  can  be  made  by 
depending  on  them.  The  percentages  of  humidity 
given  are  modified,  to  some  extent,  by  the  intensity 


EGGS    IN    COLD    STORAGE.  23 

and  distribution  of  the  air  circulation  employed.     (See 
Chapter  III  on  "Circulation.") 

CORRECT    RELATIVE   HUMIDITY  FOR  A  GIVEN  TEMPERATURE 
IN  EGG  ROOMS. 

Temperature  Relative  Humidity,       Humidity  table 

in  Decrees  F.  Per  Cent.  for  egg  rooms. 

29  78 

30  76 

31  74 

32  71 

33  69 

34  67 

35  65 

36  62 

37  60 

38  58 

39  56 

40  53 

There  are  two  kinds  of  instruments  in  use  for  de-  Hygrometers. 
termining-  humidity,  hygrometersand  psychrometers. 
The  hygrometer  depends  on  the  expansion  and  con- 
traction of  some  substance,  as  a  human  hair,  in  the 
presence  of  more  or  less  moisture  in  the  air.  The 
hair  used  is  fastened  at  one  end,  the  other  end  passing- 
around  a  pulley,  to  which  is  fastened  a  pointer,  which 
moves  over  a  graduated  arc  as  the  hair  chang-es  its 
leng-th.  The  scale  reads  from  0  to  100.  The  chief 
advantag-e  of  these  instruments  is  that  results  are 
obtained  at  once,  the  reading-  corresponding-  to  the 
percentag-e  of  saturation  or  relative  humidity;  but 
these  instruments  are  affected  by  chang-es  of  tem- 
perature, and  shocks  or  vibration  materially  affect 
the  reading-.  Further,  they  are  more  expensive  in 
first  cost,  and  not  so  convenient  to  use,  as  they  must 
hang-  for  some  time  in  the  room  to  be  tested,  while 
with  the  sling  psychrometer,  described  in  another 
paragraph,  an  observer  can  pass  from  room  to  room, 
g-etting-  observation  in  less  than  two  minutes  in  each 
room,  needing-  but  one  instrument  and  making-  all 
observations  at  practically  the  same  time. 

A  psychrometer    is    simply    two    thermometers  Psychrometers. 
mounted  on  a  frame  ;    the  bulb  of  one  being-  covered 


24  KGGS    IN   COLD   STORAGE. 

with  rnuslin  so  as  to  retain  a  film  of  water  surround- 
ing it.  The  working-  of  this  instrument  depends  on 
a  law  which  may  be  roughly  expressed,  as  "evapora- 
tion carries  off  heat."  The  evaporation  of  water  from 
the  bulb  incased  in  muslin,  known  as  the  wet  bulb, 
cools  it  somewhat,  depending-  on  how  dry  the  air  sur- 
rounding- it  may  be.  The  difference  between  the 
reading-  of  the  wet  bulb  thermometer  and  the  reading 
of  the  dry  bulb  thermometer,  when  compared  with 
reference  to  a  prepared  table,  give's  the  relative 
humidity  of  the  air  at  the  time  of  making- the  observa- 
tion. Psych rometers  are  of  two  kinds,  stationary 
and  sling-. 

The  stati°nary  psychrometer  is  essentially  like 
the  sling-  psychrometer,  both  depending-  on  the  same 
principle.  The  sling-  instrument  is  more  compact 
and  provided  with  a  handle  for  whirling-,  while  the 
stationary  instrument  is  intended  to  be  fastened 
against  the  wall,  or  on  a  post,  the  muslin  covering-  the 
wet  bulb  being  connected  by  a  porous  cord  with  a 
reservoir  of  water,  to  keep  the  supply  of  water  con- 
tinuous. This  is  essential,  as  it  takes  some  little 
time  to  obtain  a  correct  reading  with  this  pattern  of 
instrument.  For  this  reason  it  is  open  to  the  same 
objections  as  the  hygrometer.  Also,  after  short  use 
the  muslin  covering  the  wet  bulb,  and  the  cord  feed- 
ing water  to  it,  become  clogged  with  solid  matter  and 
fungous  growth  affecting  its  accuracy.  At  any  tem- 
perature below  32°  F.  this  instrument  is  useless,  as 
the  water  will  freeze  in  the  cord  supplying  the  mus- 
lin on  the  wet  bulb,  and  the  muslin  becomes  dry  in 
consequence. 

For  practical,  accurate  and  quick  results  at  any 

psychrometer.  . 

temperature  there  is  no  instrument  so  reliable  and 
convenient  as  the  sling  psychrometer,  preferably  of 
the  pattern  known  as  Prof.  Marvin's  improved  psy- 
chrometer, shown  in  the  illustration.  This  is  a 
standard  Weather  Bureau  instrument,  and  when  used 


EGGS    IN    COLD   STORAGE. 


25 


in  connection  with  the  tables  of  hu- 
midity published  by  the  bureau,  any 
needed  results  may  be  obtained  with 
a  fair  degree  of  accuracy.  The  sling 
psychrometer,  as  illustrated,  consists 
of  a  pair  of  thermometers  mounted 
on  an  aluminum  plate,  one  higher 
than  the  other,  the  lower  having-  its 
bulb  covered  with  a  small  sack  of 
muslin.  At  the«top,  the  frame  or  plate 
supporting-  the  thermometers  is  pro- 
vided with  a  handle  for  whirling-,  this  handle 
being-  connected  by  links  to  the  plate,  and 
provided  with  a  swivel  to  allow  of  a  smooth 
rotary  motion.  The  bulb  of  the  lower  ther- 
mometer is  wet  at  the  time  of  making-  an  ob- 
servation, Ihe  muslin  serving-  to  retain  a  film 
of  water,  surrounding-  and  in  contact  with 
what  is  known  as  the  wet  bulb  of  the  psy- 
chrometer. The  muslin  should  be  renewed 
from  time  to  time,  as  the  meshes  between  the 
threads  will  gradually  fill  with  solid  matter 
left  by  the  evaporation  of  the  water  and  the 
natural  accumulation  of  dust  from  the  air. 
The  muslin  in  this  condition  will  neither  ab- 
sorb nor  evaporate  the  water  readily. 

To  make  an  observation   dip  the  muslinDirectionsfor 

using1  the  sling 

covered  bulb  in  a  small  cup  or  other  wide-Psychrometer- 
mouthed  receptacle  containing-  water.  Whirl 
the  thermometer  for  ten  or  fifteen  seconds, 
then  dip  the  wet  bulb  of  the  psychrcmeter 
into  the  water  again.  Whirl  again  for  ten  or 
fifteen  seconds,  stop  and  read  quickly,  read- 
ing- the  wet  bulb  first.  Repeat  once  or  twice, 
noting-  the  reading-  each  time.  When  two 
successive  readings  of  the  wet  bulb  agree 
very  nearly,  the  lowest  point  has  been 
Dip  the  wet  bulb  only  after  the 


f 

SLING 
PSYCHRO- 
METER.   -reached. 


26  EGGS    IN    COLD   STORAGE. 

first  whirling,  as  this  is  done  only  to  make  sure 
that  the  muslin  is  thoroughly  saturated  with  water. 
If  the  water  used  is  of  nearly  the  same  temperature 
as  the  room,  correct  readings  are  sooner  obtained. 
If  the  psychrometer  and  water  are  at  a  much  higher 
temperature  than  the  air  of  the  room,  it  will  take  a 
proportionately  longer  time  to  reach  a  correct  read- 
ing, but  the  accuracy  will  not  be  impaired,  if  sufficient 
time  is  allowed  for  the  mercury  to  settle.  It  is  very 
important  that  the  muslin  covered  bulb  should  not 
become  dry  in  the  least;  it  should  be  saturated  with 
water  during  the  full  time  of  observation.  There  will 
be  no  difficulty  in  getting  accurate  readings  down  to 
29°  F.,  as  indicated  by  the  dry  bulb.  At  about  this 
temperature,  and  with  the  wet  bulb  at  about  27°  F., 
ice  will  form  on  the  wet  bulb  and  cause  the  psychro- 
meter to  become  somewhat  erratic  in  its  behavior.* 

Jt  is  difficult  to  describe  the  proper  movements 
psychrometer.  for  whirling  the  sling  psychrometer,  a  little  practice 
being  the  best  instructor.  The  handle  is  held  in 
a  horizontal  position,  the  frame  mounting  the  ther- 
mometers revolving  around  the  pivot,  after  the  man- 
ner of  the  weapon  with  which  David  slew  Goliath,  and 
from  which  our  moisture-tester  gets  the  easy  part 
of  its  name.  A  high  rate  of  speed  is  unnecessary,  a 
natural,  easy  motion  of  the  forearm  or  wrist  being  all 
that  is  required.  When  stopping  the  psychrometer 
the  arm  should  follow  the  thermometer  from  the  high- 
est point  of  the  circle  of  rotation,  whereby  the  radius 
of  the  path  of  the  psychrometer  is  increased,  and  the 
momentum  overcome.  The  stopping  can  be  accom- 
plished in  a  single  revolution,  after  a  little  practice. 
The  psychrometer  will  come  to  rest  very  nicely  by 
simply  allowing  the  arm  to  stand  still,  but  the  final 
revolution  will  be  quite  irregular  and  jerky. 

*  The  writer  is  in  receipt  of  a  special  report  on  this  point,  prepared  by 
Prof.  C.  F.  Marvin,  in  charge  of  the  instrument  division  of  the  Weather  Bureau, 
and  will  gladly  give  any  one  having  difficulty  with  the  psychrometer  at  these 
temperatures  information  so  far  as  he  can;  but  the  point  involved  is  somewhat 
intricate,  and  so  few  are  using  temperatures  as  low  as  29°  F.  that  it  is  thought 
best  to  omit  a  discussion  of  this  phenomenon. 


EGGS    IN    COLD   STORAGE. 


27 


In  making-  observation  in  a  storage  room,  the  psy- 
chrometer  should  be  held  as  far  as  convenient  from 
the  body,  and  toward  the  direction  from  which  the 
circulation  comes — the  observer  standing-  to  the  lee- 
ward, as  it  were.  In  some  cases  it  is  necessary,  or 
advisable,  to  step  slowly  back  and  forth  a  few  steps, 
and  the  observer  should  turn  his  head  from  the  di- 
rection of  the  psychrometer,  so  his  breath  will  not 
affect  the  reading.  In  reading-  a  thermometer,  read 
as  quickly  as  possible,  and  do  not  allow  the  breath  to 
strike  the  bulb.  It  is  a  common  practice  with  the 
writer  to  hold  his  breath  while  reading  a  thermome- 
ter. It  is  unnecessary  to  caution  ag-ainst  allowing-  the 
psychrometer  to  strike  any  object  while  whirling*. 
In  case  it  should,  the  observer  will  have  $5  worth  of 
experience,  but  no  psychrometer. 

RELATIVE  HUMIDITY,  PER  CENT. 


0) 

>> 

Difference  between  the  dry  and  wet  thermometers  (t—f). 

£  Table  of  rela- 
v  tive  humidity. 

•K.-*-1 

Q 

0°.5 

1°.0 

1°.5 

2°.0 

2°.5 

3°.0 

3°.5 

4°.0 

4°.5 

5°.0 

5°.S 

6°.0 

Q 

28 

94 

88 

82 

77' 

71 

65 

60 

54 

49 

43 

38 

33 

28 

7.9 

94 

89 

83 

77, 

72 

66 

61 

56 

50 

45 

40 

35 

29 

30 

94 

89 

84 

78 

73 

67 

62 

57 

52 

47 

41 

36 

30 

31 

95 

89 

84 

79 

74 

68 

63 

58 

53 

48 

43 

38 

31 

32 

95 

90 

84 

79 

74 

69 

64 

59l 

54 

50 

45 

40 

32 

33 

95 

90 

85 

80, 

75 

70 

65 

60 

56 

51 

47 

42 

33 

34 

95 

91 

86 

8ll 

75 

72 

67 

62 

57 

53 

48 

44 

34 

35 

95 

91 

86 

82 

76 

73 

69 

65 

59 

54 

50 

45 

35 

36 

96 

91 

86 

82 

77 

73 

70 

66 

61 

56 

51 

47 

36 

37 

96 

91 

87 

82 

78 

74 

70 

66 

62 

57 

52 

48 

37 

38 

96 

92 

87 

83 

79 

75 

71 

67 

63 

58 

54 

50 

38 

39 

96 

92 

88 

83 

79 

75 

72 

68 

63 

59 

55 

52 

39 

40  i 

96 

92 

88 

84 

80 

76 

72 

68 

64 

60 

56 

53 

40 

The  above  short  table  needs  no  explanation  fur- 
ther  than  has  been  already  given.  It  will  cover  any 
case  in  egg  room  observations.  This  table  was  not 
intended  for  cold  storag-e  work,  being-  a  part  of  the 
regular  humidity  tables  published  by  the  Weather 
Bureau.  The  full  set  of  tables  can  be  had  by 


table 


28  EGGS    IN   COLD   STORAGE. 

addressing-  the  chief  of  the  Weather  Bureau,  Depart- 
ment of  Agriculture,  Washington,  D.  C.  They  are 
published  in  pamphlet  form,  along1  with  tables  giving- 
dew  point  temperatures.  Observers  must  work  out 
the  small  fractions  for  themselves,  if  they  think 
necessary,  but  results  within  the  limits  covered  by 
the  table  are  near  enough  for  present  practical  pur- 
poses. 

It  is  of  no  use  to  test  for  moisture  unless  having* 
the  ability  to  control  it,  any  more  than  a  thermometer 
would  be  of  use  unless  the  means  of  regulating*  tem- 
perature were  at  hand.  Humidity  can  be  controlled 
by  ventilation  and  the  use  of  absorbents,  which  are 
considered  elsewhere. 


V'J 


A 


CHAPTER   III. 

CIRCULATION. 

vigorous  and  penetrating*  circulation  of  air  must  circulation 

*  .  .     essential. 

be  maintained  in  a  cold  storage  room  for  eggs  if 
good  results  are  to  be  insured.  The  importance  of 
this  condition,  as  applied  to  eggs  especially,  is  quite 
generally  appreciated,  and  it  is  noticeable  that  the 
warehouses  producing  the  most  perfect  work  have 
scientific  and  carefully  designed  air  circulating  sys- 
tems. It  is  also  a  fact  that  a  strong,  searching  circu- 
lation will  do  much  to  counteract  defects  in  a  cooling 
apparatus,  or  wrong  conditions  in  the  egg  room  in 
some  other  particular.  In  proof  of  this,  the  writer  is 
familiar  with  a  number  of  successful  houses  where 
prominence  is  made  of  the  air  circulating  system 
only,  some  of  the  other  conditions  being  neglected  al- 
together, or  attended  to  in  a  perfunctory  manner. 

Before  going  farther,  it  is  best  that  we  separate  circulation  n 

0  *     .  ventilation. 

circulation  from  its  tangle  with  ventilation.  These 
two  terms  are  quite  commonly  confused  when  applied 
to  cold  storage  work.  Circulation,  as  here  discussed, 
applies  to  the  motion  of  air  within  the  storage  room — 
air  currents  resulting  from  a  difference  in  tempera- 
ture of  the  air  in  different  parts  of  the  room,  or  the 
result  of  mechanical  force  applied  to  the  air  by  use  of 
fans,  blowers  or  exhausters.  In  distinction  from  cir- 
culation, ventilation  means  the  renewal  of  the  air  of  a 
storage  room,  either  by  forcing  fresh  air  from  the 
outside  atmosphere  into  the  storage  room,  or  by  ex- 
hausting the  foul  air  from  the  room.  Ventilation  is 
not  under  consideration  here,  but  will  be  taken  up  as 
a  separate  subject. 

The  reason  why  a  vigorous  and  well  distributed  circulation 

~  ^  and  moisture 

circulation  of  air  in  an  egg  room  will  give  superior  absorbing 
results  over  a  sluggish  or  partial  circulation  may  not 
be  readily  apparent.     A  circulation  of  air  is  of  benefit 
in  combination  with  moisture  absorbing  capacity  in 

29 


30  EGGS    IN    COLD   STORAGE. 

the  form  of  frozen  surfaces  or  deliquescent  chemicals. 
Stirring-  up  the  air  merely,  as  with  an  electric  motor 
fan,  without  provision  for  extracting-  the  moisture,  is 
of  doubtful  utility,  and  may,  in  some  instances,  prove 
positively  detrimental,  as  it  is  liable  to  cause  conden- 
sation of  moisture  on  the  goods,  or  walls  of  storag-e 
room,  instead  of  its  correct  resting-  place:  the  cooling- 
coils  and  absorbents.  Let  us  see  how  the  circulation  of 
air  in  a  storag-e  room  operates  to  benefit  its  condition. 
Under  head  of  temperature,  we  have  seen  that 
circulation.  foQ  evaporation  from  an  eg-g-  contains  the  putrid  ele- 
ments resulting-  from  a  partial  decomposition  of  the 
eg-g-  tissues,  and  that  the  air  of  a  storag-e  room  carries 
them  in  suspension.  It  is  probable  that  these  foul 
elements  are  partly  in  the  form  of  g-ases  absorbed  in 
the  moisture  thrown  off  from  the  egg-;  and  if,  there- 
fore, this  moisture  is  promptly  frozen  on  the  cooling- 
pipes,  or  absorbed  by  chemicals,  the  poisonous  gases 
and  products  of  decomposition  are  very  largely  ren- 
dered harmless.  This  is  also  true  of  the  germs 
which  produce  mold  and  hasten  decay,  which  are  ever 
present  in  the  atmosphere  of  a  storage  room,  being 
carried  to  a  considerable  extent  by  the  water  vapor 
in  the  air,  along  with  the  foul  matter  of  various  kinds 
referred  to.  If  the  vapor  laden  air  surrounding  an 
egg  is  not  removed  and  fresh  air  supplied  in  its  place, 
the  air  in  the  immediate  vicinity  of  the  egg  gets  fully 
charged  with  elements  which  will  produce  a  growth  of 
fungus  on  its  exterior,  affecting  and  flavoring  the  in- 
terior— the  flavor  varying  in  intensity,  depending  on 
how  thoroughly  impregnated  with  fungus-producing 
vapor  the  air  in  which  the  egg  is  kept  may  be.  In 
short,  then,  circulation  is  of  value  because  it  assists 
in  purifying  the  air.  It  should  be  kept  up  so  that 
the  air  may  be  constantly  undergoing  a  purifying 
process  to  free  it  from  the  effluvia  which  are  always 
being  thrown  off  by  the  eggs,  even  at  very  low  tem- 
peratures. It  has  been  suggested  that  a  brisk  circu- 


EGGS    IN    COLD   STORAGE.  31 

lation  of  air  which  will  keep  in  motion  the  whole 
volume  of  air  in  the  storage  room  will  have  a  purify- 
ing- influence  independent  of  any  moisture  absorb- 
ing- capacity,  but  no  satisfactory  reason  has  been 
assig-ned.  There  may  be  such  an  influence  opera- 
tive when  the  air  is  mechanically  circulated.  If  so, 
there  seems  to  be  no  scientific  or  practical  explana- 
tion of  it. 

Manv  patents  have  been   granted    for   improve- circulation  in 

0  A  natural  ice 

ments  in  storag-e  rooms  or  refrig-erators  using-  ice  only  refrigerators. 
for  a  cooling-  ag-ent;  house  refrig-erators,  refrigerator 
cars  and  refrigerator  buildings  are  represented  in 
number  about  in  order  named.  A  large  portion  of  the 
patents  granted  have  been  on  claims  for  the  improve- 
ment of  circulation,  and  this  is  the  keynote  of  what- 
ever success  has  been  attained  by  the  various  sys- 
tems which  use  ice  only  for  cooling.  As  any  system 
of  cooling  whereby  the  air  is  caused  to  circulate  in 
contact  with  melting  ice  is  now  quite  generally  re- 
garded as  obsolete  for  the  successful  refrigeration  of 
eggs  for  long  period  storage,  a  discussion  of  the 
merits  of  the  various  devices  applied  to  this  work 
will  be  omitted.*  It  may  be  said  to  their  credit,  how- 
ever, that  the  builders  of  ice  refrigerators  have  orig- 
inated ideas  on  circulation  which  have  been  of  much 
value  to  the  present-day  refrigerating  engineers,  and 
there  are  still  those  who  may  obtain  good  information 
from  this  source — the  provision  for  circulation  (or 
rather,  lack  of  circulation)  in  a  few  of  the  new  me- 
chanical cold  storage  houses  being  simply  ridiculous. 
In  the  more  progressive  mechanically  refrigerated 
houses  there  are  a  number  of  devices,  which  have 
been  introduced  for  assisting  natural  gravity  air  cir- 
culation, also  the  various  modifications  of  the  me- 


*  The  above  must  not  be  construed  as  condemning-  the  use  of  ice  as  a 
refrigerant  when  rightly  applied.  The  writer  has  in  successful  operation  a  sys- 
tem of  gravity  brine  circulation,  cooled  by  ice  and  salt,  with  which  he  will  under- 
take to  produce  at  moderate  expense  any  possible  results  in  refrigeration  down 
to  a  temperature  of  15"  F. 


32 


KGGS    IN    COLD    STORAGE. 


Questions 
rel  atinar  to 
circulation. 


Answers  to 
Query  1. 


chanical  forced  circulation  system.  Some  of  these 
will  continue  to  gain  favor  because  of  the  improved 
results  obtained  by  their  use.  The  main  requisite 
in  any  air  circulating-  system  is  an  ability  to  cause  an 
equal  distribution  of  the  moving-  air,  as  it  comes  from 
the  moisture  absorbing- surfaces,  forcing  it  uniformly 
to  all  parts  of  the  room  and  compelling-  it  to  flow 
throug-h  and  around  the.  piles  of  stored  g-oods.  As  a 
secondary  consideration  may  be  mentioned  the  equal- 
ization of  temperature  and  humidity  in  all  parts  of  the 
room.  The  writer  is  somewhat  biased  in  favor  of 
forced  circulation,  having-  developed  a  very  complete 
system  on  this  line,  with  some  new  features.  Aside 
from  a  matter  of  economy  of  space  and  operation, 
the  system  employed  matters  little,  if  an  effective  cir- 
culation is  produced. 

The  questions  bearing5  upon  circulation  contained 
in  the  list  of  inquiries  sent  out  by  the  writer  are  as 
follows : 

First. — In  piping-  your  rooms  what  provision  was 
made  for  air  circulation? 

Second. — What  difference  in- temperature  do  you 
notice  in  different  parts  of  the  same  room? 

Third. — Do  you  use  a  fan  or  any  kind  of  mechanical 
device  for  maintaining-  a  circulation  of  air  in  the  rooms? 

More  answers  were  received  on  this  subject  than 
on  the  subject  of  humidity,  but  not  exceeding-  one- 
third  contained  tangible  replies  to  all  three  inquiries. 
Several  of  the  answers  confounded  circulation  with 
ventilation,  as  before  alluded  to.  Question  1,  in  par- 
ticular, was  badly  neglected,  indicating,  no  doubt,  that 
no  provision  was  made  for  circulation  in  a  majority  of 
cases.  The  common  device  in  use  for  causing  air  to 
circulate  more  rapidly  over  the  cooling  coils,  when 
they  are  placed  directly  in  the  room,  is  some  form 
of  screen,  mantle,  apron,  false  ceiling  or  partition,  as 
illustrated  in  Figs.  3,  4  and  5.  Many  of  these  have 
been  put  up  after  the  house  has  been  in  operation  for 


EGGS    IN    COLD   STORAGE.  33 

some  time,  and  are  very  crude  affairs,  applied  in  all 
conceivable  combinations  with  the  pipe  coils.  In  some 
cases  canvas  curtains,  or  a  thin  wooden  screen,  have 
been  suspended  under  ceiling-  coils  with  a  slant  to 
cause  the  cold  air  to  flow  off  one  side,  and  with  sur- 
prising" improvement  to  the  room,  considering-  the 
simplicity  of  the  device.  Forced  circulation  with  a 
complete  system  of  distributing-  air  ducts  is  coming 
into  g-eneral  use,  as  the  meritsof  this  way  of  producing 
circulation  are  better  understood  and  appreciated. 

Query  2  was  answered  more  generally,  but  that  Answers  to 
some  of  the  answers  were  mere  guesses,  or  state- 
ments made  without  testing,  is  very  evident,  as  they 
state  that  no  difference  was  noticed  in  different  parts 
of  the  same  room.  With  open  piping  or  gravity  air 
circulation,  this  is  an  impossibility — it  is  only  possible 
with  a  perfectly  designed  forced  circulation  system. 
In  contrast  to  this  claim  some  answers  state  a  differ- 
ence in  temperature  of  as  high  as  4°  F.  to  5°  F.,  but 
most  answers  show  a  difference  of  1°  F.  to  2°  F.;  a 
few  ^°  F.  to  1°  F.;  and,  still  others,  as  before  stated, 
none  at  all.  A  marked  variation  of  temperature  in 
different  parts  of  a  room,  while  in  most  cases  caused 
by  defective  circulation,  is  due  sometimes  partly  to 
location  of  room  as  to  outside  exposure,  proximity  to 
freezing  rooms,  character  of  the  insulating  walls,  etc. 
An  egg  room  placed  over  a  low  temperature  freezing 
room  will  show  more  variation  between  floor  and 
ceiling  than  when  located  over  another  egg  room, 
conditions  being  otherwise  the  same.  Where  this 
arrangement  occurs,  and  the  egg  rooms  are  operated 
on  a  natural  gravity  air  circulation  system,  eggs  may 
be  frozen  near  the  floor,  when  a  thermometer  hanging 
at  the  height  of  a  person's  eyes  would  read  30°  F.  or 
above.  Even  with  the  very  best  insulation,  the  result 
of  this  very  common  arrangement  is  a  defective  cir- 
culation and  more  or  less  variation  in  temperature 
between  floor  and  ceiling. 


34 


EGGS    IN   COLD   STORAGE. 


Answers  to 
Query  3. 


Gravity  air 
circulation. 


In  reply  to  Question  3,  about  a  dozen  state  that 
they  are  using-  some  form  of  mechanical  forced  cir- 
culation. The  advantages  of  this  method  will  be 
discussed  quite  fully  later  on.  About  double  this 
number  are  using-  the  small  electric  fans.  These 
also  will  be  treated  in  the  discussion  of  mechanical 
air  circulation  in  another  chapter. 

As  air  circulation  is  a  somewhat  neglected  subject, 
and  comparatively  few  have  experimented  enough  to 
have  positive  opinions,  based  upon  practical  expe- 
rience, reg-arding-  the  merits  of  different  devices  and 
methods,  some  of  the  more  prominent  and  successful 
ones  are  illustrated  and  discussed  in  this  article. 

In  considering-  the  following-  outlined  arrange- 
ments  of  piping-  in  the  storag-e  room  and  the  various 
locations  of  screens,  partitions,  etc.,  in  combination 
with  the  coils,  for  the  purpose  of  separating-  the 
warm  and  cold  currents  of  air  (the  one  on  its  way 
upward  from  lower  part  of  room  to  the  top  of 
cooling-  coils;  the  other  downward  from  cooling- 
coil  toward  floor),  the  principle  on  which  this 
movement  of  air  operates  should  be  noted,  so 
that  the  underlying-  law  may  be  understood.  The 
cause  of  a  circulation  of  air  in  a  storag-e  room  with 
direct  piping-  is  a  variation  of  temperature,  which 
causes  a  difference  in  weig-ht  of  the  air  in  different 
portions  of  the  room.  The  air  in  the  immediate 
vicinity  of  the  pipes  is  cooled  to  a  lower  temperature 
than  in  the  balance  of  the  room,  causing-  it  to  drop 
toward  the  floor  by  reason  of  its  greater  specific 
gravity — what  is  designated  as  gravity  air  circulation. 
Just  as  long-  as  the  flow  of  the  refrig-erant  is  main- 
tained within  the  cooling-  pipes,  the  air  will  circulate 
by  the  action  of  gravity,  the  lig-hter  warm  air  in  top 
of  room  descending-  to  replace  the  air  in  contact  with 
pipes,  which  falls,  as  cooled,  toward  the  floor.  Should 
the  refrig-erant  passing-  through  coils  be  shut  off,  the 
cooling  effect  is  checked,  and  as  a  result  air  circula- 


EGGS    IN    COLD   STORAGE.  35 

tion  over  the  pipes  ceases.  This  should  make  plain 
the  fact  that  uniform  temperatures  in  all  parts  of  the 
room  are  not  even  an  approximate  possibility  in  any 
room  depending-  on  natural  gravity  air  circulation.  It 
may  also  be  observed  that  the  eg-g-s  exposed  to  the 
flow  of  cold  air  near  bottom  of  coils  will  stand  in  a 
dryer  and  colder  atmosphere  than  those  in  top  and 
center  of  room. 

Fig-.  1  shows  an  outline  sketch  of  piping-  suspende 
from  the  ceiling- of  a  room — the  most  unscientific  way 
possible  for  a  room  to  be  piped,  as  it  provides  for  no 


*       " 


)         '          f  j*f 

v  j  ^  ^  J  ;     (  V    j    ^    s 


air  circulation  whatever.  The  only  possible  reason 
why  air  will  circulate  over  pipes  in  this  position  is  be- 
cause of  the  fact  that  the  whole  ceiling-  is  not  covered 
by  pipes,  which  allows  of  a  partial  circulation,  as 
shown  by  the  arrows.  The  volume  of  circulation  in 
the  lower  half  of  room  is  practically  nothing-.  It  is 
larg-ely  confined  to  the  top  of  room,  the  lower  part 
being-  cooled  by  conduction  and  radiation  almost  en- 
tirely. It  may  be  asked :  How  can  a  room  be  cooled 
by  radiation?  In  the  same  way  that  a  room  is  heated 
by  radiation,  except  that  in  cooling-  a  room  the  heat  is 
radiated_/>wft  the  objects  in  the  room,  and  not  to  them, 
as  when  heating-.  This  gives  us  ample  reason  why  a 
room  should  be  cooled  by  circulating-  the  air  over 


36 


EGGS    IN   COLD   STORAGE. 


Open  side  wall 
Piping. 


frozen  surfaces  located  outside  of  the  room,  or  at 
least  in  a  position  so  that  no  radiation  or  conduction 
can  occur.  The  use  of  insulated  screens  or  mantles, 
as  shown  in  Figs.  3,  4.  and  5,  is  recommended  as  being- 
superior  to  any  arrangement  of  open  piping-;  but,  of 
course,  it  is  not  equal  to  forced  circulation,  in  which 
the  pipes  are  located  outside  of  room  entirely. 

Fig-.  2  shows  another  very  common  and  faulty 
arrang-ement  of  piping  for  cooling  an  egg  room.  The 
only  improvement  over  the  arrangement  shown  in 
Fig.  1  is  that  it  allows  of  a  moderate  action  of  gravity 


K 


f   ( 

f 


\ 


\v 


near  the  coils,  as  shown  by  the  arrows.  It  is  open  to 
the  same  objection  on  the  ground  of  conduction  and 
radiation  as  No.  1,  but  to  a  lesser  degree.  The  coils 
are  placed  a  few  inches  out  from  the  walls,  to  allow 
the  air  to  circulate  around  the  pipes  freely,  and  to 
provide  room  for  an  accumulation  of  frost.  The  top 
of  the  coil  should  be  quite  close  to  the  ceiling.  If  the 
coil  is  placed,  say  midway  between  floor  and  ceiling 
(unless  it  covers  nearly  the  whole  space),  it  is  sure  to 
result  in  the  air  becoming  stratified,  a  warm  layer  of 
air  in  top  of  room  resting  on  a  colder  one  near  floor, 
perhaps  to  an  extent  so  great  as  to  cause  a  difference 
of  10°  F.  in  temperature  between  floor  and  ceiling  of 
room.  A  case  with  exactlv  these  conditions  is  on 


EGGS    IN   COLD   STORAGE. 


37 


record.  Another  very  bad  arrangement  of  side  wall 
piping-  came  to  the  notice  of  the  writer  recently.  A 
room  exceeding-  fifty  feet  square  was  piped  completely 
around  from  floor  to  ceiling  with  the  exception  of  the 
doors.  Circulation  could  penetrate  but  a  compara- 
tively small  portion  of  the  space  in  this  room,  and  in 
a  large  area  of  the  central  portion  the  air  was  conse- 
quently very  foul,  and  mold  and  must  were  rampant. 

Fig.  3  gives  us  the  first  primitive  improvement  A 
over  open  coils,  and  it  is  along  step  in  the  right  direc-pipin£ 
tion,  but  it  fails  to  take  care  of  the  center  of  the  room, 


/'/> 


f/j. 


especially  near  the  ceiling.  The  usefulness  of  this 
device  consists  in  its  ability  to  increase  the  velocity, 
and  consequently  the  volume  of  air  passing  over  the 
cooling  coils.  The  increased  velocity  of  air  causes  it 
to  cover  a  greater  area,  and  spread  toward  the  center 
of  room  further.  The  apron  or  screen  used  before 
the  coils  should  be  constructed  of  any  moderately 
good  non-conductor.  Separating  the  warm  and  cold 
currents  of  air  increases  the  draft,  on  the  same  prin- 
ciple that  a  fire  burning  in  a  flue  creates  a  greater 
suction  or  a  more  rapid  displacement  of  air  than  when 
burning  in  the  open. 

Fig.  4  is  simply  an  addition  to  No.  3,  of  a  false 
ceiling   or    curtain    extending  well   out    toward   the 


38 


KGGS    IN    COLD   STORAGE. 


Gay's  system 
of  box  coils. 


center  of  the  room.  This  obliges  the  circulation  to 
spread  so  as  to  cover  a  large  portion  of  the  cross-sec- 
tion area  of  the  room,  as  indicated  by  the  arrows,  but 
has  the  effect  of  reducing  its  volume  to  some  extent. 
This  ceiling  apron  should  have  a  slant  of  not  less  than 
one  foot  in  ten.  It  occupies  some  considerable  space, 
but  is  richly  worth  it.  The  opening  into  outer  edge 
of  apron  in  center  of  room  need  not  exceed  three 
inches  in  depth  in  most  cases,  and,  as  some  space 
must  be  left  at  the  top  of  room  for  air  circulation 


with  the  wall  coils,  without  ceiling  apron,  not  much 
space  is  wasted  by  its  addition. 

Fig.  5  gives  us  an  entirely  different  arrangement 
of  piping,  but  with  essentially  the  arrangement  of 
aprons  shown  in  Fig.  4.  This  is  the  system  advo- 
cated by  Mr.  C.  M.  Gay  on  page  106  of  the  August, 
1897,  number  of  Ice  and  Refrigeration,  and  the 
writer  believes  it  to  be  the  best  idea  for  air  circula- 
tion of  any  having  pipes  directly  in  the  room.  The 
following  is  quoted  from  Mr.  Gay's  description: 
"  Upper  pipes  of  box  coils  should  be  about  ten  inches 
below  the  ceiling  of  the  room,  to  prevent  sweating. 
When  brine  or  ammonia  is  turned  into  these  pipes 
(as  shown  in  Fig.  5),  the  cold  air  around  the  pipes 
seeks  an  outlet  downward  and  passes  between  the 


EGGS    IN    COLD   STORAGE. 


39 


false  partition  and  the  side  wall  of  the  room,  thus 
displacing-  or  pushing-  along-  the  air  in  center  of  room, 
the  cold  air  naturally  seeking-  the  lowest  point  and  the 
warm  air  the  hig-hest  point,  each  by  reason  of  its  rela- 
tive gravity.  Thus  as  the  cold  air  falls  from  the  cool- 
ing- surfaces  it  is  replaced  by  the  warm  air  from 
hig-hest  point  in  center  of  room.  This  secures  a 
natural  circulation  and  a  dry  room,  there  being-  no 
counter-currents  nor  tendency  to  precipitate  moisture 
on  walls  or  ceiling-." 


Fie-.  6  is  the  St.  Clair  or  pipe  loft  system,  which  st.  ciair,  or 

i_  1-jj  j    i     j  t.        j     •        Pipe  loft 

has  been  applied  to  many  remodeled  overhead  ice  system, 
cold  storag-es,  by  placing-  the  pipes  in  a  part  of  what 
formerly  was  the  ice  space,  and,  in  some  cases,  using- 
the  original  air  ducts  for  circulation.  The  sketch 
here  shown  represents  one  room  only,  but  as  many  as 
five  or  six  different  floors  have  been  operated  from  a 
single  pipe  loft,  using-  one  main  air  duct  for  the  down, 
and  one  for  return  air  circulation,  each  floor  having-  a 
connection  with  the  mains  in  which  the  flow  of  air  is 
reg-ulated  by  g-ates.  A  better  arrang-ement,  when 
more  than  one  floor  is  to  be  operated  on  this  system, 
is  to  have  independent  ducts  for  each  room,  and  the 
cooling-  coils  separated  likewise;  then  any  room  or 
rooms  may  be  used  for  other  products  at  any  time 


40 


EGGS    IN    COLD   STORAGE. 


Size  of 
egg  rooms. 


when  free  of  eggs.  This  latter  arrangement,  of 
course,  requires  more  space  and  is  slightly  objection- 
able on  this  account.  The  circulation  is  more  vigor- 
ous with  this  system  than  with  any  pipe-in-the-room 
system,  depending-  on  the  law  that  the  higher  the 
column  of  air  the  stronger  the  draft,  on  the  same 
principle  that  a  tall  chimney  gives 
greater  draft  than  a  short  one.  It  is, 
therefore,  better  than  any  room  pip- 
ing, and  has  the  added  advantage  of 


f     / 


being  easily  shut  off  from  the  room,  when  the  weather 
no  longer  requires  cooling  power.  The  need  of  keep- 
ing the  air  of  the  room  from  contact  with  the  frost 
on  pipes  will  be  looked  into  under  ventilation  and 
absorbents. 

Refrigerator  rooms  for  the  storage  of  eggs  should 
not  exceed  thirty  or  thirty-five  feet  in  width.  The 
cross-section  illustrations  of  rooms  cooled  by  gravity 
air  circulation,  which  have  already  been  illustrated,  and 
the  two  sketches  shown  herewith  of  the  arrangement 
of  air  distributing  ducts  used  in  two  systems  of  forced 
circulation,  are  sufficient  to  show  why  a  room  should 
not  be  excessively  wide  as  compared  to  its  height.  In 
a  wide  room  it  may  be  seen  that  the  air  from  cold 
air  ducts,  in  case^of  forced  circulation,  or  from  the 


BGGS    IN   COLD   STORAGE.  41 

bottom  of  cooling-  coils  in  case  of  room  piping-,  is 
required  to  pass  over  more  eggs  in  its  flow  to  the 
return  air  duct  or  false  ceiling-.  The  eg-g-s,  then, 
are  not  all  exposed  to  the  same  drying-  and  puri- 
fying- influence,  because  the  air  as  it  comes  from  the 
cooling-  coils  is  at  its  maximum  dryness  and  purity, 
and  becomes  impregnated  with  moisture  and  impuri- 
ties more  and  more  as  it  flows  through  the  goods.  If 
the  length  of  piles  of  goods  is  great  from  side  to  cen- 
ter of  room,  the  eggs  in  top  and  center  of  room  will  be 
exposed  to  air  which  is  much  more  impure  and  moist 
than  the  eggs  first  exposed  to  the  flow  of  air  directly 
from  cooling  coils.  This  applies  more  especially  to 
the  gravity  systems  of  air  circulation.  With  forced 
circulation,  the  air  moves  probably  three  or  four 
times  as  fast  as  when  a  gravity  system  is  used,  con- 
sequently the  air  in  top  and  center  of  room  does  not 
carry  the  amount  of  impurities  that  it  does  if  depend- 
ing only  on  gravity  for  its  motion.  This  fact  in  itself 
is  a  very  good  reason  why  forced  circulation  is  supe- 
rior to  any  gravity  system. 

It  has  been  claimed  that  eggs  will  lose  weight  by 
shrinkage  more  rapidly  when  stored  in  a  room  iH 
which  the  air  is  circulated  by  mechanical  means  than 
in  a  room  operated  on  the  gravity  air  circulation  prin- 
ciple. This  assertion  is  based  on  the  assumption 
that  the  air  is  circulated  at  a  much  higher  velocity 
when  forced  circulation  is  employed,  and  is  only 
partly  true  because  no  account  is  taken  of  humidity. 
If  the  humidity  was  the  same  in  both  cases,  the  claim 
would  be  strictly  true.  Every  intelligent  housewife 
knows  that  linen  hung  in  the  open  air  to  dry,  will  be 
freed  of  moisture  quicker  when  a  strong  breeze  is 
blowing,  than  when  the  air  is  nearly  still.  The  same 
principle  applies  moderately  to  eggs  in  a  refrigerator 
room.  With  the  same  per  cent  of  moisture,  the  more 
rapid  the  circulation  the  greater  the  evaporation  from 
the  eggs;  but  if  the  facts  were  known,  it  would  be 


42  KGGS    IN    COLD   STORAGE. 

found  in  every  instance  where  trouble  from  excessive 
shrinkage  of  the  egg  meat  was  experienced,  that  no 
attempt  was  made  to  regulate  humidity.  It  is  as  easy 
to  control  humidity  as  it  is  to  control  temperature,  and 
with  no  bad  effect  on  the  other  conditions  in  the  storage 
room,  if  we  go  about  it  in  the  right  way.  Ventilation 
and  the  use  of  absorbents  are  agents  which  can  be 
utilized  for  this  purpose. 

toie  With  a  vigorous  circulation  of  air,  an  egg  room  may 
circulation.  be  maintained  at  a  humidity  which  would  be  disas- 
trous, if  only  a  sluggish  circulation  was  operative. 
Why?  Because  a  brisk  movement  of  air  around  the 
eggs  removes  the  moisture  and  impurities  as  fast  as 
given  off  by  the  eggs.  They  are  not  allowed  to  remain 
in  the  vicinity  of  the  eggs  to  work  mischief,  but  are 
promptly  hurried  off  to  the  cooling  coils  or  absorb- 
ents, where  they  are,  for  the  most  part,  rendered 
harmless.  This  seems  to  explain  how  eggs  may  be 
carried  sweet,  and  with  very  little  evaporation,  when  a 
well  distributed  forced  circulation  of  air  is  employed. 
With  any  gravity  system,  the  circulation  of  air  can- 
not be  controlled,  because  depending  on  the  tempera- 
ture of  refrigerant  flowing  in  the  pipes  for  its  velocity; 
and  as  the  temperature  of  refrigerant  is  regulated  to 
correspond  with  outside  weather  conditions  (lower  in 
warm  weather  and  higher  in  cold  weather)  the  velocity 
of  circulation  is  not  constant — being  least  in  the  cold 
weather  of  fall,  when  it  is  most  needed.  With  a  good 
system  of  forced  circulation  installed,  the  problem, 
then,  is  to  proportion  the  circulation  of  air  to  the 
humidity.  We  might  take  our  humidity  at  the  degree 
which  would  come  naturally,  if  no  attempt  were  made 
to  control  it,  and  speed  our  blower  up  or  down  to  pro- 
duce a  circulation  to  match,  but  it  would  probably  be 
best  to  provide  a  circulation  which  would  handle  a 
large  volume  of  air  at  a  brisk  speed,  and  raise  our 
humidity  to  as  high  a  point  as  would  be  safe.  Refer- 
ring to  the  table  of  correct  humidity  given  in  Chapter 


EGGS    IN   COLD   STORAGE.  43 

II,  page  23,  it  will  be  noted  that  an  arbitrary 
percentage  is  given  for  each  temperature.  These 
are  the  most  desirable  percentages  of  air  moisture 
for  average  conditions  of  circulation,  as  when  using 
the  most  scientific  forms  of  gravity  air  circulation 
during  warm  weather.  When  using  a  good  system 
of  forced  circulation,  these  percentages  may  be  in- 
creased moderately.  Exactly  how  much  will  depend 
on  conditions,  and  can  be  told  only  by  trial,  but  it  will 
be  much  greater  in  proportion  at  the  high  tempera- 
tures, ranging  from  2  per  cent  or  3  per  cent  on  the  low, 
to  7  per  cent  or  8  per  cent  on  higher  temperatures. 

Before  taking  up  the  forced  circulation  systems  Electric  fan  in 

egg  room  not 

proper,  the  electric  fans  used  in  so  many  large  houses  desirable. 
will  be  considered.  These  little  fans  are  a  four  to 
six-bladed  disk  fan,  from  twelve  to  eighteen  inches  in 
diameter,  attached  directly  to  the  shaft  of  a  J/s  or 
^ -horse  power  electric  motor.  /The  wires  supplying 
the  electric  current  to  the  motor  are  usually  con- 
nected to  the  socket  for  an  ordinary  incandescent 
lamp.  Electric  fans  are  usually  placed  on  the  floor 
in  the  back  end  of  alleyway,  or  in  an  opening  in  the 
piles  of  goods,  creating  a  draft  of  air  from  one  ex- 
tremity of  the  room  toward  the  other.  As  the  air 
from  the  fan  will  follow  a  path  of  least  resistance,  the 
circulation  resulting  from  their  operation  is  largely 
confined  to  the  alleyways  or  openings  in  the  piles  of 
stored  goods — it  does  not  penetrate  through  and  be- 
hind the  piles  of  eggs.  It  may  be  readily  observed 
that  this  is  of  doubtful  utility,  and  may  at  times  lead 
to  positive  harm  by  causing  a  condensation  of  mois- 
ture upon  goods  as  a  result  of  the  comparatively 
warm,  moisture  laden  upper  strata  of  air  coming  in 
contact  with  the  flow  of  cold  air  from  the  cooling 
pipes.  Electric  fans  have  also  been  utilized  to  propel 
the  air  from  the  cooling  pipes,  for  which  purpose  they 
are  placed  in  an  opening  in  a  screen  or  mantle  cover- 
ing the  pipes,  forcing  the  cooled  air  outwardly  into  the 


44  EGGS    IN    COLD    STORAGE. 

room.  In  any  other  position,  they  are  only  useful  as  a 
"talking*  point,"  as  it  is  likely  to  impress  a  prospective 
customer  favorably  with  the  cooling-  power  of  a  refrig- 
erator, to  allow  him  to  stand  for  a  few  seconds  in  the 
breeze  created  by  one  of  these  higii-speed  fans.  The 
use  of  electric  fans  has  been  adopted  to  an  extent  not 
warranted  by  the  results  possible  to  attain  with  them, 
and  their  use  will  no  doubt  be  gradually  discontinued 
as  the  fallacy  of  the  idea  becomes  apparent. 
Primitive  The  first  svstem  of  true  forced  circulation  to  con- 

torccQ  a, ir  •* 

circulation.  sider  is  not  illustrated  and  needs  no  sketch  to  explain 
the  working-  of  it,  as  there  are  practically  no  distribut- 
ing- air  ducts,  the  cold  air  being-  forced  into  the  room 
at  two  or  three  larg-e  opening's,  and  taken  out  in  the 
same  way.  There  are  two  prominent  houses  using 
an  air  system  constructed  on  these  lines,  one  having 
the  cold  air  inlet  near  floor  and  warm  air  outlet  near 
ceiling-,  the  other  having  both  cold  and  warm  air  open- 
ings near  ceiling.  No  distribution  of  circulating  air 
of  any  consequence  is  provided,  the  idea  being  simply 
to  cool  the  room  by  forcing  in  air  which  has  been 
cooled  by  coming  in  contact  with  cooling  pipes  located 
outside  of  the  rooms.  The  cold  air  is  taken  in  at  one 
extremity  of  room  and  the  warm  air  out  at  the  other, 
or  the  cold  air  is  taken  in  at  ends  of  room  and  warm 
air  out  at  center,  or  the  reverse.  This  is  what  may 
be  called  a  primitive  form  of  forced  circulation,  and  is 
quite  similar  to  the  systems  of  indirect  steam  heating 
as  first  employed.  It  needs  no  argument  to  show  that 
a  room  equipped  in  this  way  has  varying  degrees  of 
temperature,  humidity  and  circulation,  depending  on 
the  remoteness  or  proximity  to  the  direct  route  be- 
tween cold  air  inlet  and  warm  air  outlet — the  air  mov- 
ing through  the  area  of  least  resistance,  which  is 
usually  along  the  center  alley  of  room. 

Linde-British          Fig.   7  shows   the  arrangement  of   ducts  for  air 

air-circulation  3         . 

system.  circulation  used  in  the  Linde-British  air  system;  a  a, 

cold  air  ducts;   b  b,  warm  air  duct.     This  system  of 


EGGS    IN    COLD    STORAGE.  45 

refrigeration  originated  in  Europe,  and  has  found 
favor  to  some  extent  on  this  side  of  the  water,  three 
houses  known  to  the  writer  being-  operated  on  this 
system.  Mr.  E.  H.  Johnson  describes  the  apparatus 
used  in  cooling,  purifying  and  circulating  the  air  on 
page  96  of  the  February,  1898,  issue  of  Ice  and  Refrig- 
eration. This  consists  essentially  of  a  tank  containing 
brine,  which  is  cooled  by  direct  expansion  piping. 
Slowly  revolving  in  the  tank,  with  a  portion  of  their 
surface  exposed  above  the  surface  of  the  brine,  are 
large  metallic  disks.  A  fan  causes  the  air  to  circu- 


late  rapidly  over  the  brine  moistened  surfaces  of  the 
disks,  and  the  moisture  is  extracted,  and  impurities 
and  odors  absorbed  by  the  cold  brine.  In  a  modifica- 
tion of  this  apparatus  the  direct  expansion  coils  do  the 
cooling  and  take  the  place  of  the  disks  as  well.  The 
coils  are  exposed  to  the  air  circulation,  and  the  brine  is 
pumped  over  them  in  a  shower,  a  shallow  pan  or  tank 
being  provided  under  coils  as  a  reservoir  and  recep- 
tacle for  the  brine — the  same  brine  flowing  over  coils 
again  and  again.  It  has  been  claimed  for  this  system 
that  almost  any  product  can  be  stored  in  different 
rooms,  all  of  which  were  fed  by  the  same  air  circuit 
and  cooling  apparatus,  without  any  injury  to  the  most 
sensitive.  A  statement  of  this  kind  must  first  be 


46 


EGGS    IN    COLD    STORAGE. 


proven  before  we  can  accept  it.  There  is  no  doubt, 
however,  but  that  some  good  features  are  embodied 
in  above  described  apparatus.  It  is  well  known  that 
water,  and  especially  salt  water,  has  a  great  affinity 
for  impurities  contained  in  the  air,  and  when  the  air 
is  circulated  in  contact  with  the  brine,  as  in  the  Linde 
system,  many  of  the  gases  and  impurities  common  to 
a  storage  room  are  absorbed.  That  they  are  ab- 
sorbed to  any  greater  extent  than  when  the  moisture 
is  simply  frozen  on  the  pipe  coils,  the  writer  is  not 
prepared  to  assert.  An  objection  to  this  brine  or  wet 
surface  air  cooling  is  the  liability  of  trouble  when 
brine  gets  polluted  with  impurities.  After  some  use 
the  brine  will  no  longer  act  as  a  purifier,  and  in  this 
condition  will  contaminate,  rather  than  purify,  the 
air.  If  attended  to,  this  trouble  can  be  prevented  by 
a  periodical  renewal,  or  by  supplying  a  certain  amount 
of  fresh  brine  at  regular  intervals  and  allowing  a 
portion  to  overflow.  In  discussing  absorbents  we 
will  find  a  description  of  a  device  which  seems  to  have 
all  the  advantages  of  the  Linde  method,  and  without 
some  of  the  objections. 

The  location  of  air  ducts  as  adopted  by  the  Linde- 
British  company  seems  to  call  for  some  attention.  It 
is  evident  from  their  location  that  gravity  is  depended 
upon  for  a  circulation  of  air  near  floor,  as  both  warm 
and  cold  air  ducts  are  placed  on  ceiling  of  room.  The 
flow  of  air  into  room  is  controlled  by  means  of  sliding 
gates,  which  are  adjusted  to  openings  placed  five  or 
six  feet  apart  in  the  air  duct.  This  does  not  provide 
a  well  distributed  circulation,  as  those  goods  directly 
opposite  openings  in  cold  air  ducts  will  be  exposed  to 
a  sharp  blast  of  air,  while  others  get  practically  none. 
As  a  result  of  placing  the  cold  air  duct  on  ceiling, 
there  will  be  little  or  no  movement  of  the  air  near 
floor,  when  rooms  are  filled  with  goods. 

Fig.  8  shows  a  cross-section  of  a  room  fitted  with 
a  system  of  air  ducts  and  false  ceiling  for  the  circu- 


EGGS    IN    COLD    STORAGE. 


47 


lation  of  air  in  a  cold  storage  room,  which  the  writer 
has  developed  after  several  seasons'  experiment, 
and  which  is  regarded  as  very  nearly  theoretically 
perfect.  In  practical  working-  it  gives  very  superior 
results,  and  is  believed,  by  those  who  are  using-  it,  to 
be  in  advance  of  any  other  system  now  in  use.  By 
referring-  to  the  sketch  it  may  be  seen  that  the  air  is 
forced  to  cover  very  uniformly  the  entire  cross-sec- 
tion area  of  the  room — a  result  not  possible  with  any 
other  device.  This  is  obtained  by  the  use  of  a  false 
ceiling,  b  b,  perforated  at  intervals  with  small  holes 


/« 


v 


the  "Cooper 
system"  of 
forced  air 
circulation. 


which  covers  the  whole  ceiling  of  room ;  and  the  side 
air  duct,  a  a,  perforated  with  small  holes  on  top,  bot- 
tom and  sides.  The  air  from  cooling  coils  is  forced 
into  ducts,  a  a,  and  flows  out  through  the  perforations. 
Passing  through  the  piles  of  eggs,  as  shown  by  the 
arrows,  the  air  moves  upward  through  the  perfora- 
tions in  the  false  ceiling,  and  thence  through  space 
between  false  ceiling  and  ceiling,  to  cooling  coils 
again.  This  circulation  is  actuated  by  an  exhauster, 
or  blower,  preferably  located  on  the  main  cold  air 
duct,  between  the  cooling  coils  and  cold  air  ducts,  a  a. 
This  has  a  tendency  to  put  the  egg  room  itself  under 
a  slight  pressure,  and  the  coil  room  under  a  vacuum. 
In  this  way  the  air  leakage  from  outside,  if  there  is 


48  EGGS    IN   COLD   STORAGE. 

any,  is  into  the  coil  room,  and  not  into  the  storage 
room.  The  perforations  for  outflow  of  air  from  cold 
air  duct,  a  a,  are  twice  as  numerous  on  bottom  as  on 
the  top,  and  some  are  placed  in  the  face  or  side  of 
duct  also.  The  perforations  are  comparatively  small 
holes  placed  quite  near  tog-ether,  obviating-  all  strong- 
drafts,  and  at  the  same  time  insuring-  a  very  pene- 
trating- circulation  which  will  not  allow  of  any  dead 
corners.  The  false  ceiling-  is  perforated  likewise,  the 
holes  being-  most  numerous  throug-h  the  center  of 
room  at  farthest  point  from  cold  air  ducts,  and  more 
widely  separated  as  they  approach  sides  of  room 
directly  over  cold  air  duct.  If  air  ducts  are  correctly 
proportioned,  the  perforations  properly  located  and  of 
correct  size,  and  eg-g-s  are  piled  uniformly  from  side 
toward  center  of  room,  the  air  is  forced  to  percolate 
throug-h  the  piles  of  eg-g-s  where  its  presence  has  such 
a  salutary  effect,  for  reasons  already  discussed.  The 
exhauster  for  handling-  the  air  can  be  placed  in  almost 
any  location  handy  to  power,  and  the  air  conducted  to 
it,  but  a  more  desirable  arrang-ement  is  a  direct  con- 
nected or  a  direct  belted  electric  motor.  Then  the 
fan  may  be  placed  advantageously  to  get  direct  and 
shorter  air  ducts,  saving  both  space  in  the  storage 
room  and  expense  in  construction. 

A  saving  of  space  can  be  obtained  by  using  this 
tiois  tern a~  system  of  air  circulation,  amounting  in  some  cases  to 
fully  10  per  cent  of  the  total  space  cooled,  and  a  sav- 
ing of  5  per  cent  can  be  had  in  any  house,  if  skill  and 
care  are  used  in  arranging  cooling  coils  and  air  ducts. 
Where  rooms  are  moderately  high  the  space  over  a 
hallway  or  corridor  may  be  utilized  for  cooling  coils. 
As  the  cooling  coils  are  located  entirely  outside  of  the 
storage  room  proper,  the  room  itself  can  be  filled 
with  goods  snug  up  to  the  false  ceiling  at  the  top  and 
against  air  ducts  on  sides.  The  side  ducts  and  false 
ceiling  only  occupy  about  two  inches  of  space  in  their 
respective  locations,  so  the  space  occupied  by  the  air 


EGGS    IN   COLD   STORAGE.  49 

system  is  very  small.  Storage  men  will  at  once  ap- 
preciate that  a  saving-  of  even  5  per  cent  in  space  adds 
that  much  to  the  profits  of  the  season's  business,  as 
it  is  as  expensive  to  cool  vacant  space  as  it  is  to  cool  it 
when  occupied  by  goods. 

As  an  objection  to  the  forced  circulation  system,  g.  fans 
it  has  been  urged  that  the  expense  of  running  fans 
continuously  for  handling  the  air  was  so  large  as  to 
be  a  serious  item  of  expense.  With  a  well  constructed 
apparatus  and  a  large  light  weight  fan  wheel  running 
at  a  slow  speed,  the  air  in  a  room  containing  15,000 
cubic  feet,  which  will  store  about  5,000  cases  of  eggs, 
may  be  circulated  with  an  expenditure  of  effort  not 
exceeding  one-half  a  horse  power. 

The  selection  of  a  fan  for  propelling  the  air  is  of 
considerable  moment  when  installing  an  air  circulat- 
ing system  in  a  cold  storage  room.  Fans  also  play  an 
important  part  in  handling  air  for ^ventilating,  and  the 
merits  of  the  different  kinds  and  forms  of  fans  will  be 
discussed  under  "ventilation." 


CHAPTER  IV. 

VENTILATION. 

value  of  T  N  discussing-  humidity  and  circulation,  it  has  been 

ventilation.  J 

1  explained  how  a  large  portion  of  the  gases  of  de- 
composition and  impurities  of  various  kinds,  which 
are  incident  to  the  presence  of  perishable  products  in 
cold  storage,  are  carried  by  the  moisture  existing-  in 
the  air,  and  that  when  this  moisture  is  frozen  on  the 
cooling  pipes,  or  absorbed  by  chemicals,  the  foul  mat- 
ter is  largely  rendered  harmless.  It  may  now  be 
noted  further  that  even  with  a  good  circulation  and 
ample  moisture  absorbing  capacity,  there  will  still 
be  some  impurities  and  gases,  detrimental  to  the  wel- 
fare of  the  stored  goods,  which  have  little  or  no  affin- 
ity for  the  water  vapor  in  the  air,  and  consequently 
accummulate  in  the  storage  room.  Ventilation  is 
necessary  to  rid  a  refrigerator  room  of  these  perma- 
nent gases.  The  introduction  of  a  large  volume  of 
fresh  air  is  not  essential,  however,  for  the  purpose  of 
purifying  rooms  in  which  eggs  are  stored,  because 
the  accumulation  of  permanent  gases  in  an  egg  room 
is  quite  slow,  comparatively  (as  in  rooms  where  well 
ripened  fruit  is  stored);  but  a  small  supply  of  fresh 
air  continuously,  or  at  regular  intervals,  is  of  much 
benefit. 
Ventilation  by  This  subject  of  ventilation  for  refrigerator  rooms 


has  been  very  much  talked  about  recently,  but  about 
which  really  little  is  known,  so  far  as  any  tangible  in- 
formation is  concerned.  Some  of  the  more  progress- 
ive cold  storage  managers  have  given  some  attention 
to  this  part  of  the  business,  but  many  of  the  largest 
and  best  known  houses  do  not  ventilate  their  rooms  at 
all,  except  perhaps  during  the  winter  or  spring,  when 
rooms  are  aired  out  for  the  purpose  of  whitewashing. 
In  some  cases  the  change  of  air  incident  to  opening 
and  closing  of  doors,  when  goods  are  placed  in  stor- 
age or  removed  therefrom,  is  relied  on  to  supply  ven- 

50 


EGGS    IN    COLD   STORAGE.  51 

Illation.  This  is  quite  inefficient,  because  eggs  are 
mostly  stored  during  two  or  three  months  in  the 
spring,  and  removed  from  storage  during  the  fall  and 
winter,  leaving  three  or  four  months  when  no  fresh 
air  of  consequence  can  penetrate  to  the  room,  except 
as  the  doors  may  be  opened  for  the  purpose  of  taking 
the  temperature  of  the  room.  Furthermore,  this 
kind  of  ventilation  during  the  warm  weather  of  sum- 
mer and  during  a  large  part  of  the  spring  and  autumn 
months  is  worse  than  no  ventilation  at  all.  Some  stor- 
age men  even  take  so  radical  a  position  on  this  matter 
of  opening  doors  during  warm  weather,  as  to  insist 
that  the  door  shall  not  be  opened  for  the  purpose  of 
reading  the  thermometer.  A  double  window  is  placed 
in  the  door  of  each  room,  with  the  thermometer  hang- 
ing so  that  it  can  be  read  from  the  outside  without 
opening  the  door.  While  the  writer  has  not  practiced 
this  method,  it  seems  to  be  a  good  idea,  and  it  is  cer- 
tainly preferable  to  ventilating  the  room  through 
doors  which  open  to  the  outside  air.  When  doors 
into  rooms  open  into  a  corridor,  the  evil  can  be  partly 
prevented  by  piping  the  corridor  overhead,  so  that 
the  moisture  and  impurities  may  be  taken  up  in  this 
way;  but  opening  the  door  or  window  of  a  storage 
room  directly  to  the  outside  air  when  the  temperature 
outside  is  materially  higher  will  always  result  in 
more  or  less  bad  effect  on  the  goods,  as  a  result  of  the 
water  vapor,  in  the  warmer  incoming  air  being  con- 
densed on  same. 

Another  source  of  ventilation  similar  in  its  results 
to  the  opening  of  a  door  or  window  is  that  resulting 
from  the  leakage  of  air  directly  into  the  storage  room, 
through  the  pores  and  crevices  in  the  walls  around  the 
doors  and  windows,  etc. — leakage  of  air  literally — air 
that  gets  in  when  everything  is  supposed  to  be  closed. 
The  amount  is  usually  imperceptible,  but  is  enough 
in  some  houses  to  be  a  serious  detriment  to  the  quality 
of  work  done.  In  small  houses  with  large  outside  ex- 


52  EGGS    IN   COLD   STORAGE. 

posure  and  poor  insulation  this  air  leakage  is  consid- 
erable, but  in  the  big-  refrigerators  of  several  hundred 
thousand  cubic  feet  capacity,  and  with  thorough  insu- 
lation, it  is  reduced  to  practically  nothing.  The  loss 
of  refrigeration  caused  by  air  leakage,  while  of  some 
importance,  is  of  small  moment  beside  the  bad  effects 
resulting  from  the  moisture  and  impurities  brought 
in  by  the  warm  air  from  the  outside.  The  value  of 
prime,  tight  insulation,  as  a  conserver  of  refrigera- 
tion, aside  from  a  matter  of  keeping  out  the  warm, 
moist  air,  is  well  enough  understood  not  to  need  re- 
peating here,  but  a  word  about  windows  and  doors  is 
properly  in  line  with  the  present  discussion. 
use  of  windows  Rather  than  consider  what  might  be  a  good  way 

for  eg-g-  rooms.  -" 

of  placing  windows  in  a  cold  storage  building,  their 
use  should  be  discouraged.  Even  with  four  or  five 
separate  glass,  divided  by  air  spaces,  and  with  all 
joints  set  in  white  lead,  the  loss  of  refrigeration  is 
large.  It  is  also  very  difficult  to  fit  insulation  around 
the  window  frame  so  as  to  make  a  good  job;  and  even  if 
a  passable  job  were  practicable,  the  expense  of  putting 
in  windows  is  sufficient  to  condemn  their  use.  The 
increased  fire  exposure  is  of  some  consequence,  too, 
and  with  the  low  cost  of  electric  light,  windows  should 
not  be  thought  of  for  cold  storage  work.  Barring  the 
small  amount  of  heat  given  off,  the  incandescent  elec- 
tric lamp  is  an  ideal  device  for  lighting  cold  storage 
rooms,  as  the  air  is  not  vitiated  as  when  using  gas, 
kerosene  or  candles. 

Doors  which  will  shut  tight,  forming  a  nearly  per- 
fect air  seal,  with  a  small  amount  of  pressure,  have 
long  been  wanted  for  cold  storage  rooms.  Most  of  the 
ordinary  bevel  doors,  either  with  or  without  packing 
on  the  bevel,  will  not  shut  even  approximately  tight; 
and  in  operation  nine  out  of  every  ten  stick  and  re- 
fuse to  open  except  after  many  persuasive  kicks  and 
surges — we  all  know  how  it  is.  While  having  no  in- 
terest in  furthering  the  sale  of  the  Stevenson  door, 


EGGS    IN    COLD    STORAGE.  53 

which  will  be  advertised  in  Ice  and  Refrigeration,  the 
writer  believes  it  to  be  head  and  shoulders  above  any- 
thing else  in  this  line,  and  does  not  hesitate  to  recom- 
mend it  to  those  wanting-  a  door  which  will  prevent 
air  leakage.  The  price  is  very  reasonable,  consider- 
ing- the  excellent  material  and  fine  work  put  into  its 
construction.  The  slig-ht  additional  cost  over  the 
common  door  will  be  quickly  saved,  by  reason  of  its 
quick  action — opening-  instantly  when  the  lever  is 
grasped. 

Having-  g-ot  into  the  subject  of  air  leakag-e,  we  may 
as  well  see  how  it  is  caused  and  why  it  must  beairleaka^e- 
g-uarded  ag-ainst.  It  is  operative  from  the  same  law 
as  gravity  air  circulation,  which  was  explained  quite 
thoroug-hly  in  the  first  part  of  the  chapter  on  "  Circu- 
lation." When  the  outside  air  is  warmer  than  that 
of  the  storage  room,  the  air  in  the  storage  room  pro- 
duces a  pressure  on  the  floor  and  lower  part  of  the 
room,  by  reason  of  its  greater  weight,  and  conse- 
quently it  seeks  to  escape  there.  If  there  are  open- 
ings near  the  floor  where  the  air  can  flow  out,  and 
others  at  the  ceiling  -or  upper  part  of  the  room,  the 
air  will  flow  in  at  the  top  and  out  at  the  bottom  of  the 
room.  Reverse  the  conditions  of  temperature,  and 
the  direction  of  flow  of  air  is  also  reversed.  That  is, 
when  the  air  outside  is  colder  than  the  air  of  the 
room,  the  cold  air  will  flow  into  the  room  at  the  bot- 
tom and  the  comparatively  warm  air  of  the  room  out 
at  the  top.  This  action  is  nicely  illustrated  by  not- 
ing the  air  currents  in  a  door  which  is  opened  into  a 
cold  room  when  the  temperature  is  very  warm  out- 
side. The  warm  air  rushes  in  at  the  top  of  door  and 
the  cold  air  of  room  out  at  the  bottom.  In  cold 
weather  the  direction  of  air  flow  will  be  reversed. 

Perfect  inclosing  walls  for  a  cold  storage  room 
would  be  perfectly  air  tight,  as  they  would  be  if  lined  stora^e 
with  sheet  metal,  with  soldered  joints.     The  interior 
conditions  would  then  be  under  more  perfect  control. 


54  EGGS    IN    COLD    STORAGE. 

It  is  hardly  necessary  to  do  this  (although  it  has 
been  done  in  case  of  some  old  time  houses),  as  a 
practically  tight  job  may  be  had  by  using-  the  right 
materials,  well  put  on.  Air  leakage  may  not  be  ex- 
actly ventilation,  but  it  is  a  kind  of  ventilation  which 
has  given  the  writer  some  trouble  in  the  past,  and 
does  still,  consequently  the  difficulties  of  operating 
a  house  with  defective  insulation  and  large  outside 
exposure,  and  still  turn  out  first-class  eggs,  are  very 
thoroughly  appreciated. 

4JnfmruItebela'  Methods  of  ventilation  which  are  permissible 
when  applied  to  the  work  of  supplying  fresh  air  to 
ordinary  structures  are  generally  dangerous  when 
used  to  ventilate  cold  storage  rooms.  The  problem 
in  ventilating  non-insulated  structures  is  merely  the 
supplying  of  fresh  air  from  the  outside  without  caus- 
ing a  marked  change  in  the  temperature,  and  without 
creating  strong  drafts.  Air  for  the  ventilation  of 
refrigerator  rooms,  during  warm  weather,  must  be 
of  very  nearly  the  same  temperature  and  relative 
humidity  as  the  air  of  the  room  to  be  ventilated,  and 
free  from  the  germs  which  hasten  decay  and  cause  a 
growth  of  fungus  on  the  products  in  storage.  If  a 
door  or  window  of  a  storage  room  is  opened  directly 
to  the  outside  atmosphere,  there  will  be  little  or  no 
circulation  of  air  into  and  out  of  the  room  when  the 
temperature  outside  and  in  is  about  the  same,  unless 
the  wind  should  be  favorable.  As  we  cannot  ventilate 
in  this  way  when  the  air  outside  is  colder  than  the 
storage  room,  on  account  of  freezing  the  eggs,  and  the 
introduction  of  fresh  air,  which  is  warmer  than  the 
storage  room,  is  not  permissible,  for  reasons  already 
given,  the  matter  reduces  itself  to  not  ventilating  at 
all  during  warm  weather  (which  most  houses  prac- 
tice), or  of  properly  cooling  and  purifying  the  air  be- 
fore forcing  it  into  the  storage  room.  It  will  bear 
repeating  that  it  is  positively  bad  practice  to  allow  air 
from  the  outside  to  get  into  an  egg  room  during  the 


EGGS    IN   COLD   STORAGE.  55 

summer  months,  also  during*  a  large  portion  of  the 
spring-  and  fall  months,  unless  cooled  and  purified 
first.  The  fact  that  we  cannot  see  the  moisture  de- 
posited in  the  form  of  beads  of  water,  or  floating-  in 
the  air  in  the  form  of  fog-  or  mist,  does  not  indicate 
that  it  is  not  present.  The  sling-  psychrometer,  de- 
scribed in  discussing-  humidity,  will  give  an  accurate 
indication  of  the  result  of  this  unscientific  method  of 
ventilating-. 

Any  natural  means  of  handling-  air  for  ventilation  *°}Jf  Bri**s 
is  inaccurate  and  inoperative,  or  it  may  be  positively  ventllatlon- 
harmful,  except  under  favorable  conditions.  If  de- 
pending- on  natural  gravity  for  ventilation  it  will  be 
g-uesswork,  to  a  greater  or  less  extent,  because  de- 
pending on  conditions  which  vary  with  the  season, 
temperature,  direction  and  force  of  the  wind,  etc. 
The  late  Robert  Brig-g-s,  an  authority  on  ventilation, 
makes  a  concise  statement  of  the  advantages  of  using 
fans  for  ventilation,  in  his  "  Notes  on  Ventilating  and 
Heating."*  He  says:  "It  will  not  be  attempted  at 
this  time  to  argue  fully  the  advantages  of  the  method 
of  supplying  air  for  ventilation  by  impulse  through 
mechanical  means — the  superiority  of  forced  ventila- 
tion, as  it  is  called.  This  mooted  question  will  be 
found  to  have  been  discussed,  argued  and  combated 
on  all  sides  in  numerous  publications,  but  the  con- 
clusion of  all  is,  that  if  air  is  wanted  in  any  particular 
place,  at  any  particular  time,  it  must  be  put  there, 
not  allowed  to  go.  Other  methods  will  give  results 
at  certain  times  or  seasons,  or  under  certain  con- 
ditions. One  method  will  work  perfectly  with  certain 
differences  of  internal  and  external  temperature, 
while  another  method  succeeds  only  when  other 
differences  exist.  .  .  .  No  other  method  than 
that  of  impelling  air  by  direct  means,  with  a  fan,  is 
equally  independent  of  accidental  natural  conditions, 
equally  efficient  for  a  desired  result,  or  equally 

*  Proc.  Am.  Soc.  Civil  Engineers,  May,  1881. 


56 


KGGS    IN   COLD   STORAGE. 


Plenum  vs. 
vacuum 
method  of 
ventilation. 


Advantages  of 
the  plenum 
or  pressure 
method. 


controllable  to  suit  the  demands  of  those  who  are 
ventilating-." 

There  are  two  general  methods,  with  some  modifi- 
cations, for  handling-  air  for  ventilation:  The  plenum 
or  pressure  method,  in  which  the  fresh  air  is  forced 
into  the  room ;  and  the  vacuum  or  exhaust  method,  in 
which  the  foul  air  is  drawn  out.  The  exhaust  method 
is  to  be  avoided  for  ventilating-  cold  storag-e  rooms, 
for  reasons  which  we  shall  see  presently.  With  this 
method,  sometimes  the  exhaust  steam  from  an  engine 
is  utilized  to  induce  a  draft  of  air  upward  from  storag-e 
room,  by  heating-  the  air  in  a  stack  or  ventilation  flue 
connected  at  its  lower  end  with  the  room  to  be  ven- 
tilated. In  some  cases  no  provision  is  made  for  an  in- 
flow of  fresh  air,  in  which  case  it  will  seep  in  at  every 
crack,  crevice  and  pore  (by  reason  of  the  partial 
vacuum  created  by  exhausting-  the  foul  air  out),  bring- 
ing-  a  load  of  moisture  and  g-erms  of  disintegration 
into  the  storag-e  room.  This  exhaust  steam  method 
is  no  different  in  its  result  than  if  a  fan  were  placed 
so  as  to  draw  the  air  out  of  the  storag-e  room  under 
conditions  which  are  otherwise  the  same  as  described 
in  connection  with  the  exhaust  steam  method.  Should 
we  provide  an  inlet  for  fresh  air,  throug-h  proper  ab- 
sorbents, the  same  law  would  be  operative,  only  to  a 
lesser  degree,  as  a  partial  vacuum  must,  in  any  case, 
be  created  before  the  air  from  outside  would  flow  into 
the  room,  tending- to  the  dang-erous  air  leakag-e  already 
fully  discussed. 

The  plenum  or  pressure  method  is  by  far  the  best 
for  our  purpose.  The  air  should  be  forced  into  the 
room  by  a  fan,  after  first  properly  cooling-,  drying 
and  purifying-  it.  An  outlet  for  the  escape  of  the  foul 
gases  which  it  is  desired  to  be  rid  of,  should  be  pro- 
vided near  the  floor,  as  these  gases,  by  reason  of 
their  greater  gravity,  tend  to  accumulate  in  the  lower 
part  of  the  room.  It  will  be  observed  that  forcing 
the  fresh  air  in  creates  a  pressure  inside  the  room, 


EGGS    IN    COLD   STORAGE.  57 

and  if  there  is  any  air  leakage,  it  will  be  outwardly 
from  the  room — exactly  the  way  we  want  it  to  go. 
Having-  brought  our  subject  to  the  point  where  it  is 
found  that  the  best  way  to  ventilate  is  by  the  use  of 
fans  forcing-  the  air  into  the  storag-e  room,  we  will 
determine  what  type  of  fan  is  best  adapted  to  our 
needs.  What  is  said  of  fans  for  ventilation  is  equally 
true  if  they  are  to  be  used  for  forced  air  circulation, 
described  under  head  of  circulation. 

It  is  admitted  by  a  majority  of  experts  on  air  mov-  ™ 
ing-  machinery  that  the  disk  or  propeller  wheel  ty pe  type  of  fan- 
of  fan,  throug-h  which  the  air  moves  parallel  to  the 
axis  of  fan,  is  not  efficient  or  desirable  for  work  where 
the  air  has  to  travel  throug-h  a  series  of  tortuous  air 
ducts,  as  in  the  forced  air  circulation  system  for  cold 
storag-e  work,  or  for  ventilation  purposes  where  there 
is  some  resistance.  Where  any  resistance  of  import- 
ance is  encountered,  the  disk  fanjnust  be  driven  at  a 
hig-h  rate  of  speed,  and  at  an  immense  loss  of  power,  to 
compel  it  to  deliver  its  full  quota  of  air.  Another  dis- 
advantage of  the  disk  type  is  the  difficulty  of  belting 
to  the  shaft,  or  of  g-etting-  power  to  the  fan  in  any 
form,  if  it  is  inclosed  entirely  in  an  air  duct.  The  disk 
type  will  therefore  be  dismissed,  and  the  well  known 
centrifug-al,  or  peripheral  discharg-e  fan  taken  up. 

This  type  of  fan  draws  the  air  in  at  its  center  Advantages  of 

J  r  the  centrifugal 

parallel  to  the  shaft,  and  delivers  it  at  rig-ht  ang-les 
the  shaft  at  the  periphery  or  rim  of  the  fan  wheel, 
the  law  g-overning-  its  action  being-  the  well  under- 
stood centrifug-al  force,  which  is  commonly  illustrated 
when  we  see  the  mud  fly  from  a  bug-g-y  wheel  or  the 
water  off  a  grindstone.  The  advantag-e  of  these  fans 
over  the  disk  type  is  that  the  centrifugal  action  set 
up  by  the  rotary  motion  of  the  fan  is  utilized  to  give 
velocity  to  the  air  in  its  passage  over  the  fan  blades. 
In  the  selection  of  a  fan  for  the  purpose  of  forced  cir- 
culation in  the  storage  room,  or  for  forcing  in  fresh 
air  for  ventilation,  it  should  be  noted  that  a  large  slow 


58  EGGS    IN    COLD   STORAGE. 

running-  fan  wheel  is  very  much  more  economical  of 
dtffertntspeaeds  power  than  a  small  fan  running-  at  a  hig-h  rate  of  speed, 
both  doing-  the  same  amount  of  work.  The  loss  of 
ref  rig-eration,  too,  in  a  rapidly  moving-  fan,  is  of  conse- 
quence, because  the  air  is  warmed  by  impact  with  the 
blades.  The  proportion  of  power  saved  by  the  use  of 
a  larg-e  fan  running-  at  a  slow  rate  of  speed,  rather  than 
a  small  fan  running-  at  a  hig-h  rate  of  speed,  both  de- 
livering- the  same  amount  of  air,  is  almost  phenomenal, 
and  does  not  seem  at  all  reasonable  at  first  view.  The 
volume  of  air  delivered  by  a  fan  varies  very  nearly  as 
the  speed,  while  the  power  required  varies  about  as 
the  cube  of  the  speed.  That  is,  doubling-  the  speed 
doubles  the  volume  of  air,  while  the  power  required  is 
increased  eig-ht  times.  We  will  take  a  specific  case. 
A  45-inch  fan  wheel,  revolving-  at  a  speed  of  200  revo- 
lutions per  minute,  delivers,  say,  5, 000  cubic  feet  of  air 
per  minute,  and  requires  but  one-quarter  of  a  horse 
power  to  operate  it.  If  the  speed  is  increased  to  400 
revolutions,  the  volume  of  air  delivered  will  be  only 
about  10,000  cubic  feet,  while  the  power  required  to 
drive  it  will  be  raised  to  two  horse  power.  These 
fig-ures  are  theoretical,  but  within  certain  limits  are 
approximated  in  practice. 
LOSS  of  power  por  use  [n  coid  storage  work  the  objection  com- 

from  excessive  °  J 

fan  weights.  mon  to  nearly  all  the  air  moving-  machinery  found 
listed  by  the  manufacturers  is  the  seemingly  unnec- 
essary amount  of  metal  used  in  its  construction. 
The  heavy  weig-ht  of  the  fan  wheels,  and  the  larg-e 
diameter  of  shaft  necessitated  by  such  weig-ht,  causes 
much  friction  on  the  journals,  so  that  when  running- 
at  the  slow  speeds  desirable  for  cold  storag-e  work, 
more  power  is  required  to  overcome  the  mechanical 
friction  than  is  actually  required  to  move  the  air.* 


*Having  been  unable  to  find  a  fan  wheel  well  suited  to  the  requirements  of 
cold  storage  duty,  the  writer  has  designed  and  constructed  a  line  of  fan  wheels 
especially  for  slow  speeds,  which  are  amply  strong  and  capable  of  moderately 
high  speeds,  when  necessary,  but  are  very  much  lighter  than  most  fans  on  the 
market,  and  consume  proportionately  less  power  in  mechanical  friction. 


EGGS    IN   COLD   STORAGE.  59 

No  doubt  the  high  speeds  necessary  for  some  work 
have  obliged  the  manufacturers  to  make  their  fans 
amply  strong-  for  the  highest  speeds,  consequently 
they  are  not  economical  for  the  slower  speeds.  It 
would  not  be  appropriate  for  a  person  to  fan  himself 
with  a  dinner  plate — it  would  do  the  work,  but  would 
not  be  economical  of  power. 

So  far  we  have  found  out  what  kind  of  ventilation 
is  not  desirable,  and  have  an  inkling-  of  what  kind 
would  be  desirable.  The  question  before  us  now  is  to 
properly  treat  the  air  before  introducing-  it  into  the 
storag-e  room,  so  that  it  may  be  fresh — /.  <?.,  pure 
oxyg-en  and  nitrog-en,  without  excessive  moisture, 
and  free  from  the  impurities  and  germs  which  may 
contaminate  the  product  which  is  being-  refrig-erated. 

The  questions  referring- to  temperature  contained  Questions 
in  the  letter  of  inquiry  sent  out  by  the  writer  before  ventilation. 
beg-inning-  to  write  these  articles  are  as  follows : 

First. — What  plan  do  you  pursue  in  ventilating 
egg  rooms? 

Second. — Under  what  circumstances  and  how  often 
do  you  ventilate? 

Third. — How  often  do  you  consider  it  advisable  to 
make  a  complete  change  of  air? 

Outside  of  a  bare  dozen,  the  replies  on  this  much-  Miscellaneous 

replies  to  ven- 

talked-of  subject  were  of  no  value  whatever  for  our  tiiation queries 
purpose.  Most  of  those  answering-  do  not  ventilate  ; 
many  others  get  their  ventilation  through  the  opening 
of  doors;  some  ventilate  through  an  elevator  shaft,  by 
opening  doors  at  top  and  bottom,  etc.  Only  three  or 
four  are  properly  cooling  and  drying  the  air  before  in- 
troducing it  into  the  egg  rooms.  One  successful  stor- 
age manager  says  that.  "It  is  trouble  enough  to  take 
microbes,  bacteria,  moisture,  etc.,  out  of  one  batch  of 
air"  (meaning  the  air  in  his  rooms  at  the  beginning 
of  the  season),  without  adding  to  his  troubles  by  send- 
ing in  more  air  loaded  down  with  the  same  mischief 
makers.  As  before  pointed  out,  unless  the  air  to  be 


60  EGGS    IN   COLD   STORAGE. 

used  for  purifying-  the  rooms  is  itself  first  cooled  and 
purified,  this  man's  idea  is  perfectly  correct. 
impurities  ex-         The  free  outside  air  during- warm  weather,  espe- 

isting-inthe          .  ... 

free  outside  air.  cially  in  the  vicinity  of  our  large  cities,  contains, 
among-  many  others,  g-erms  which  produce  the  para- 
sitic plant  growth  which  is  called  mildew  or  mold.  The 
exhalation  from  the  lung-s  of  the  many  animals  and 
men  who  inhabit  our  cities,  and  the  evaporation 
from  the  dust,  dirt  and  decaying  matter  of  various 
kinds  peculiar  to  the  street,  render  the  air  a  recep- 
tacle and  conveyor  for  impurities  and  germs  of  many 
species.  The  species  of  germs  which  concern  us  are 
active  in  proportion  to  the  temperature  and  humidity 
of  the  air.  In  a  warm  atmosphere  which  contains 
much  moisture  they  take  root  and  grow  rapidly, 
throwing  off  more  germs  of  their  kind,  which  impreg- 
nate the  air  in  an  increasing  ratio  as  the  humidity  and 
temperature  are  increased.  The  humidity  of  the 
outside  air  is  not  necessarily  increased  with  the  tem- 
perature, but  it  is  always  increased  to  some  extent, 
and  as  the  temperature  of  the  outside  air  rises  we 
must  necessarily  be  more  and  more  careful  how  we 
treat  and  handle  the  air  which  we  are  to  use  for  the 
ventilation  of  refrigerator  rooms. 

^  *s  rea-^^y  understood  why  it  is  necessary  to  cool 
the  air  before  introducing  it  into  the  storage  room  to 
at  least  as  low  a  temperature  as  that  of  the  room  to 
be  ventilated,  and  some  cold  storage  managers  have 
ventilated  on  this  basis,  thinking  that  this  was  all 
that  was  necessary  for  successful  ventilation.  Air 
cooled  only  to  the. temperature  of  the  storage  room 
will  be  saturated  with  moisture  at  that  temperature, 
and  will  be  in  condition  to  develop  mold  rapidly.  An 
improvement  on  this  manner  of  handling  is  to  cool 
the  air  to  be  used  for  ventilation  to  a  few  degrees  (say 
five  or  six)  below  the  temperature  of  the  storage 
room.  The  air  will  then  be  rendered  as  dry  as  that  of 
the  storage  room.  This  is  a  good  method  of  ventila- 


EGGS    IN   COLD   STORAGE.  61 

tion,  and  one  which  the  writer  has  practiced,  but  it  is 
open  to  criticism,  because  of  the  fact  that  the  air  is 
not  purified  fully  at  the  same  time  it  is  cooled  and 
dried.  If  the  air  is  first  cooled  to  several  degrees 
below  the  temperature  of  the  room  to  be  ventilated, 
it  will  be  of  benefit  to  the  room,  if  not  overdone,  but 
in  results  will  not  be  equal  to  a  system  to  be  described 
and  illustrated  further  on  in  this  article. 

Several  houses  known  to  the  writer  ventilate  by  inefficient 
letting  the  warm  outside  air  in  at  a  high  point  of  the 
ceiling,  directly  over  cooling  coils,  expecting  that  the 
air  will  be  properly  cooled  and  dried  before  it  flows 
into  the  room  itself.  The  same  objections  are  appli- 
cable to  this  system  as  are  applicable  to  any  plan  of 
ventilating  where  the  air  is  cooled  only  to  the  tem- 
perature of  the  room  to  be  ventilated,  because  the 
air  will  be  at  the  saturation  point,  and  will  therefore 
raise  the  humidity  of  the  room,  as  well  as  introduce  a 
quantity  of  germs  and  impurities. 

If  we   ventilate    by  simply   cooling   the  air,   the  simPle  air 

of         .  cooler. 

simplest  and  most  effective  method,  as  shown  in 
Fig.  9,  is  to  take  the  air  from  as  high  and  sheltered  a 
place  as  is  accessible  about  the  building;  draw  it 
down  over  frozen  surfaces  in  the  form  of  brine  or 
ammonia  pipes,  which  may  be  arranged  anywhere 
along  the  wall  of  a  room,  outside  of  the  storage  en- 
tirely, if  more  convenient.  An  exhaust  fan  takes  the 
air  from  the  coils  in  the  ventilating  flue  and  forces  it 
into  the  room  to  be  ventilated,  allowing  it  to  escape  in 
the  neighborhood  of  the  cooling  coils,  where  it  will 
mix  with  the  air  circulation,  and  flow  into  the  room 
through  the  regular  channel.  It  is  necessary  to  pro- 
vide an  outlet  for  the  escape  of  foul  air  whenever 
fresh  air  is  forced  into  the  room.  This  outlet  should 
be  near  the  floor,  and  of  about  the  same  area  as  the 
inlet  pipe.  A  steam  coil  may  be  provided  beneath 
the  cooling  coil  in  ventilating  flue,  as  shown  in  the 
sketch,  for  the  purpose  of  melting  the  frost  off  the 


62 


EGGS    IN    COLD   STOKAGK. 


I3RIMEOR 

AMMONIA 
COIL, 


Coi  u 


FIG.    9. 


pipes.     The  casing  around  the  cooling  coil  should,  of 
course,  be  insulated  moderately,  as  well  as  the  pipe 


EGGS    IN    COLD    STORAGE.  63 

leading-  from  it  to  the  storage  room, wherever  exposed 
to  the  warm  outside  air.  The  size  of  apparatus 
necessary  for  this  purpose  need  not  be  large,  as  the 
quantity  of  air  necessary  for  ventilating  egg  rooms  is 
quite  small,  comparatively. 

"Americus"  mentions  a  method  of  washing  air 
ventilation,  in  the  July,  1898,  number  of  Ice  and  Re- 
frigeration, which  seems  to  have  advantages.  The 
idea  is  to  draw  or  force  air  through  a  body  of  water 
or  brine  by  immersing  the  intake  pipe  so  that  the  air 
will  bubble  up  through  the  liquid.  This  seems  quite 
simple,  but  when  it  comes  to  forcing  air  through  a 
liquid  with  a  fan  it  is  not  so  simple,  as  nothing  short 
of  an  air  pump  will  drive  air  through  a  pipe  submerged 
as  above  described,  unless  the  opening  from  pipe  is 
placed  quite  near  the  surface  of  the  liquid;  in  which 
case  the  benefit  to  the  air  is  very  small.  Experiments 
conducted  by  the  writer  along  this  line  were  consid- 
ered failures. 

Shown  in  Fig.  10  is  what  appears  as  a  rather  com- 
plicated  apparatus,  but  on  investigation  it  proves  to 
be  quite  simple.  There  are  three  members  to  this 
system,  as  follows:  First,  The  air  washing  tank,  in 
which  the  air  flows  upward  against  a  rain  of  water 
from  a  perforated  diaphragm  above,  as  clearly  shown 
in  the  sketch.  This  not  only  cools  the  air  to  the  tem- 
perature of  the  water,  say  55°  F.  or  60°  F.,  but  it  also 
takes  out  a  large  portion  of  the  impurities  of  various 
kinds.  From  the  washing  tank  the  air  is  passed  on, 
in  a  comparatively  pure  and  cool  state  to  be  still  fur- 
ther cooled.  Second,  The  cooling  tank,  in  which  the 
air  is  cooled  to  several  degrees  lower  temperature 
than  that  of  the  storage  room.  This  removes  the 
moisture  which  holds  in  suspension  the  few  impuri- 
ties which  may  have  passed  the  washing  tank,  the 
moisture  being  deposited  on  the  frozen  surfaces 
within  the  cooler.  From  the  cooler  the  air  is  passed 
into,  third,  the  drying  box,  which  contains  chloride  of 


64 


EGGS    IN   COLD   STORAGE. 


EGGS    IN    COLD   STORAGE.  65 

calcium.  This  chemical  is  a  well  known  absorber 
of  moisture,  what  is  technically  known  as  a  deliques- 
cent substance.  If  moisture  of  any  account  passes 
the  cooler  it  is  surely  stopped  in  the  dryer,  which 
" makes  assurance  doubly  sure,"  so  far  as  delivering 
a  pure,  dry  air  is  concerned.  The  "microbes,  bac- 
teria, moisture,  etc."  (which  influenced  the  gentle- 
man  mentioned  previously  not  to  ventilate),  are  ef- 
fectually disposed  of  by  this  method.  It  would  be  a 
hardy  germ,  indeed,  that  would  not  succumb  to  such 
vigorous  treatment. 

The  volume  of  air  necessary  for  ventilating-  a 
given  size  of  egg  room  can  only  be  estimated,  and 
probably  no  two  storage  men  will  agree  as  to  what  is 
a  correct  quantity.  Some  say  that  the  introduction 
of  a  volume  of  air  equal  to  that  of  the  room  to  be 
ventilated  should  take  place  each  day;  others  twice 
each  day;  some  even  take  so  radical  a  view  of  it  as  to 
say  the  oftener  the  better  if  the  air  is  properly  dried 
and  cooled.  This  is  of  course  true  enough,  but  the 
foul  gases  which  we  can  be  rid  of  by  ventilation  ac- 
cumulate but  slowly  in  an  egg  room,  and  it  is  probable 
that  the  introduction  of  a  volume  of  fresh  air,  properly 
treated,  equaling  that  of  the  egg  room,  twice  each 
week  will  be  ample  for  the  purpose  of  keeping  the 
room  in  good  condition,  and  in  most  cases  once  each 
week  may  do  nearly  as  well.  There  is  much  to  be 
developed  yet  in  the  direction  of  ventilation  of  refrig- 
erator rooms,  more  particularly  in  the  way  of  some 
method  of  knowing  when  a  room  requires  ventilating. 
Perhaps  Prof.  Siebel  or  some  equally  bright  chemist 
may  be  able  to  assist  us  on  this  point  by  informing  us 
what  the  gases  are  which  we  must  dispose  of,  and 
indicate  some  simple  method  of  determining  their 
presence,  and  in  what  proportion. 

All  that  has  been  said  about  ventilation  so  far 
applies  only  to  the  ventilation  of  cold  storage  rooms 
when  the  air  without  is  warmer  than  the  air  of  the 


66  EGGS    IN   COLD    STORAGE. 

storage  room.  We  will  now  give  our  attention  to 
another  kind  of  ventilation,  that  is  applicable  when 
the  air  without  is  at  about  the  same  temperature  as 
the  storage  room,  or  at  some  degree  lower.  This 
will  be  designated  as  cold  weather  ventilation,  as  this 
term  seems  to  express  its  function  perfectly. 
SiadstoraCe in  -^  ^as  ^onS  been  a  well  understood  fact  that  eggs 
cooi  weather.  an(j  other  products  held  at  about  the  same  or  a  higher 
temperature  take  more  harm  in  cold  storage  during 
the  cool  or  cold  weather  of  fall  and  winter  than  during 
a  long-  carry  throug-h  the  heated  term.  Much  has 
been  said  and  written  about  why  the  old  style  over- 
head ice  cold  storag-es  g"ive  such  poor  results  during 
fall  and  winter,  the  reason  assig-ned  being-  lack  of 
circulation,  as  the  meltag-e  of  ice  ceases  when  the 
cool  weather  comes.  This  is  true;  further,  the  large 
body  of  ice  becomes  an  evaporating-  surface,  and  the 
dirt  and  impurities  which  are  found  in  all  natural  ice, 
to  a  greater  or  less  extent,  have  accumulated  on  the 
top  of  this  ice,  and  the  evaporation  which  takes  place 
carries  gases  from  this  miscellaneous  matter  into  the 
air  of  the  storage  room,  with  consequent  bad  results. 
In  some  houses  this  may  be  avoided  by  closing  the 
trap  doors  covering  circulation  flues,  but  it  is  seldom 
done,  and  in  many  houses  it  is  impossible. 
Pipe  cooled  Now  are  we  who  cool  our  storage  rooms  with  brine 

rooms  in  .  . 

cold  weather.  Or  ammonia  pipes  very  much  better  off  in  this  one  re- 
spect than  those  who  have  these  much  despised  over- 
head ice  cold  storages?  Our  rooms  are  cooled  by 
frozen  surfaces,  on  which  accumulates  the  evaporation 
from  the  goods  in  store,  which,  as  we  have  already 
plainly  seen,  contains  much  foul  matter  and  impurities. 
Precisely  as  in  the  ice  cold  storages,  the  cooling  sur- 
faces, which  absorb  moisture  during  warm  weather, 
become  evaporating  surfaces,  and  give  back  to  the  air 
of  the  room  a  considerable  portion  of  the  various  im- 
purities and  germs  which  have  been  accumulated  dur- 
ing the  warm  weather  of  summer.  To  make  this  point 


EGGS    IN    COLD    STORAGE.  67 

more  plain  it  may  be  considered  thus:  During-  the 
period  when  the  outside  air  is  considerably  warmer 
than  the  air  of  the  storage  room  it  is  necessary  to  keep 
some  refrigerant  at  work  cooling-  the  air  within.  This 
is  usually  done  by  circulating-  brine  or  ammonia 
throug-h  pipes,  and  the  air  of  the  room  is  circulated  in 
contact  with  the  pipes.  When  the  outside  tem- 
perature is  hig-h,  more  of  the  refrig-erant  must  be 
circulated,  or  its  temperature  must  be  lowered; 
as  the  weather  turns  cooler  in  the  fall,  less  re- 
frigerant, or  the  same  amount  at  a  higher  temper- 
ature, must  be  circulated,  and  when  the  air  with- 
out reaches  the  temperature  of  the  room,  the 
circulation  of  refrigerant  must  be  discontinued  al- 
together. When  this  is  done  the  moisture  on  the 
cooling  pipes  begins  to  evaporate.  This  evaporation 
added  to  that  which  is  given  off  by  the  eggs  them- 
selves soon  renders  the  air  saturated  with  very  im- 
pure and  poisonous  vapors,  which  cause  the  eggs  to 
deteriorate  very  rapidly. 

The  influence  which  the  temperature  of  the  refrig-  influence  of 

&    temperature  of 

erant  flowing  in  the  cooling  pipes  has  on  the  condition  refrigerant  in 

cooling-  pipes. 

of  a  storage  room  may  be  better  understood  by  tak- 
ing a  specific  case:  A  room  with  a  temperature  of 
33°  F.  and  a  humidity  of  70  per  cent  has  a  dew  point 
(temperature  at  which  the  air  precipitates  moisture) 
of  25°  F.  Therefore  any  cold  surface  (as  a  pipe  sur- 
face), having  a  temperature  of  25°  F.  or  lower,  will 
attract  moisture  when  exposed  to  the  air  of  the  room. 
If  the  pipe  surfaces  are  heavily  coated  with  frost,  as 
they  usually  are  as  cold  weather  approaches,  the  frost 
acts  as  an  insulator,  and  the  refrigerant  flowing  in 
pipes  must  be  at  a  considerably  lower  temperature 
than  the  air  of  the  room,  or  no  moisture  is  attracted. 
We  have  all  noted  how  the  accumulation  of  moisture 
on  pipe  coils  is  slower  and  slower  as  the  thickness  in- 
creases, until  finally  a  limit  is  reached  where  no  more 
frost  will  form;  yet  owing  to  the  largely  increased 


68  EGGS    IN    COLD    STORAGE. 

surface  the  room  can  be  kept  at  its  normal  tempera- 
ture. If  pipes  are  badly  loaded  with  frost,  sometimes 
no  absorption  of  moisture  will  take  place  when  the 
refrigerant  flowing'  in  the  coils  is  10°  or  15°  below  the 
temperature  of  the  room.  The  surface  exposed  to 
the  air  of  the  room,  whether  in  the  form  of  frost  or 
otherwise,  must  beat  or  below  the  temperature  of  the 
dew  point,  or  no  moisture  will  be  absorbed.  The 
value  of  suitable  moisture  absorbing-  surfaces  as  the 
cool  weather  of  fall  and  winter  approaches  cannot  be 
overestimated,  as  many  have  found  to  their  sorrow 
that  two  weeks'  stay  in  cold  storag-e  under  bad  condi- 
tions in  cold  weather  will  do  more  harm  to  the  eggs 
than  four  months  during-  hot  weather. 

The  remedy  for  this  trouble  is  found  in  keeping 
the  air  of  the  room  from  coming-  in  contact  with  the 
poisonous  frost  which  has  been  accumulated  on  the 
pipes  during-  their  period  of  duty  during-  warm 
weather;  or  what  is  still  a  better  way  is  to  not  allow 
the  frost,  to  accumulate  on  the  pipes  at  all,  by  using-  a 
device,  described  further  on  under  head  of  absorb- 
ents. How  to  keep  the  air  from  contact  with  the  frost 
on  pipes  is  not  an  easy  matter,  and  in  case  of  piping- 
suspended  directly  in  the  room  it  is  an  impossi- 
bility. 
Evaporation  With  a  system  of  screens  arranged  around  coils, 

from  frost  J 

accumulated  on  as  described  in  the  first  part  of  the  paper  on  circula- 

cooling-  pipes.  L 

tion,  trap  doors  may  be  fitted  to  the  opening's  and  the 
air  circulation  shut  off  in  this  way;  but  the  simplest 
and  best  way  is  to  equip  the  rooms  with  forced  cir- 
culation, and  locate  the  pipes  outside  of  the  room  en- 
tirely. Then  it  is  only  a  matter  of  shutting-  off  the 
circulation  over  coils,  allowing-  it  to  continue  throug-h 
a  by-pass,  or  if  the  device  shortly  to  be  described  is 
used,  the  circulation  may  be  allowed  to  continue  over 
coils.  It  seems  quite  clear,  from  what  has  been  writ- 
ten, why  a  storage  room  gets  foul  quickly  during  cool 
weather,  and  also  that  the  bad  conditions. may  be  bet- 


EGGS    IN    COLD   STORAGE.  69 

tered  by  cold  weather  ventilation.  The  harm  result- 
ing- from  the  foul  evaporation  from  frost  on  cooling- 
pipes  may  be  obviated  by  not  allowing-  contact  between 
it  and  the  air  of  room,  but  the  evaporation  from  the 
eg-g-s  themselves  must  be  taken  up  by  other  means 
when  cooling-  surfaces  are  no  long-er  operative. 

By  carefully  observing-  conditions  a  storag-e  room 
mav  nearly  always  be  kept  in  prime  condition  during- ventilation, 
cold  weather  by  no  other  means  than  the  introduction 
of  fresh  outside  air  at  as  frequent  intervals  as  rig-ht 
conditions  of  temperature  and  humidity  will  permit. 
It  is  quite  safe  to  force  in  plenty  of  air  which  has 
about  the  same  temperature  and  humidity  as  the 
room  to  be  ventilated.  There  are  few  impurities  in 
the  clear,  crisp  air  of  a  brig-ht  fall  day,  and  many  such 
are  available  for  our  purpose  in  the  latitude  of  Min- 
nesota and  New  York,  and  a  somewhat  smaller  num- 
ber, perhaps,  in  the  latitude  of  Iowa  or  Ohio.  It  is  only 
a  matter  of  handling-  the  free  air  of  heaven  under- 
standing-ly.  One's  impressions,  however,  will  hardly 
do  in  judging-  what  air  is  g-ood  to  use  for  ventilating- 
purposes.  If  you  have  a  brig-lit,  clear  day,  or,  what  is 
still  better,  a  clear,  cold  nig-ht,  which  has  the  appear- 
ance of  being-  what  you  want,  g-et  out  your  sling- 
psychrometer  and  set  all  g-uesswork  aside.  It  is 
frequently  possible  to  fill  your  eg-g-  rooms  with  fine, 
pure  air  at  a  temperature  about  the  same  as  that  of 
the  room,  as  early  as  the  latter  part  of  October,  if 
you  are  watching1  for  the-opportunity.  Provide  a  g-ood 
big"  fan  wheel,  which  will  handle  a  larg-e  volume  of  air 
in  a  short  time,  and  when  conditions  are  rig-ht  blow 
your  rooms  full  of  it.  Repeat  this  whenever  the 
weather  conditions  will  permit. 

We   may   now   consider   cold  weather  ventilation 
under  another  condition,  viz.:  When  it  is  colder  out- weather- 
side  than  inside  the  storage  room.  Whenever  the  out- 
side air  is  8C  or  10°  below  that  of  the  storag-e  room  it 
is  always  perfectly  safe  to  introduce  it  into  the  stor- 


70  KGGS    IN   COLD   STORAGK. 

age  room,  after  it  has  been  first  warmed  to  the  tem- 
perature of  the  room  to  be  ventilated.  That  is,  it  is 
safe  so  far  as  introducing-  moisture  or  impurities  is 
concerned.  If  we  should  ventilate  in  this  way  con- 
tinuously our  humidity  would  be  lowered  to  a  point 
where  the  eggs  might  suffer  from  evaporation.  It  is 
necessary,  therefore, that  observation  of  the  humidity 
of  the  room  so  ventilated  be  taken,  so  that  this  kind 
of  ventilation  may  not  be  overdone. 
Manner  of  in-  The  method  of  getting-  air  into  the  rooms  under 

troducmg-  air.  & 

these  last  two  systems  of  ventilation  is  of  no  special 
moment,  except  that  it  be  under  control,  and  we  have 
already  noted  that  the  only  good  way  of  handling-  air 
wras  by  the  use  of  fans,  preferably  large  and  of  light 
weight,  and  running  at  a  slow  speed.  Where  the 
forced  circulation  is  installed,  it  is  sometimes  practi- 
cable to  so  connect  the  fans  used  for  this  purpose, 
that  cold  weather  ventilation  may  be  handled  by  them; 
but  a  separate  fan  is  much  better,  and  while  seeming 
more  complicated  is  really  simpler  to  operate,  because 
handled  independently.  When  using  an  independent 
fan  or  when  using  the  forced  circulation  fan  for  ven- 
tilating, the  fresh  air  mixes  with  the  circulation  and 
is  well  distributed  by  it  to  various  parts  of  the  room. 
The  ventilation  of  cold  storage  rooms  is  not  a 
matter  which  can  be  safely  left  to  such  help  as  may 
be  at  hand,  and  if  good  results  are  to  be  secured  "  the 
boss"  should  see  to  it  himself.  Cold  weather  venti- 
lation, especially,  must  be  handled  scientifically  or 
trouble  may  result  instead  of  benefit.  No  absolute 
rules  can  be  given  for  handling  ventilation  because  of 
widely  varying  conditions,  but  if  what  has  been  writ- 
ten is  read  and  studied  carefully  the  subject  can  be 
taken  up  intelligently  and  followed  out  to  its  legiti- 
mate conclusion. 


T 


CHAPTER  V. 

ABSORBENTS. 

HE  use  of  absorbents  in  cold  storage  rooms  has  Purifying  air 

Toy  absorbents. 

been  common  since  the  industry  was  in  its  in- 
fancy; their  use  originating-,  no  doubt,  from  an  appre- 
ciation of  the  fact  that  the  air  of  a  storage  room 
quickly  became  too  moist  and  impure  to  do  the  work 
of  preservation  perfectly.  When  absorbents  and  ven- 
tilation are  applied  to  refrigerator  rooms  they  prac- 
tically have  one  duty  in  common — that  of  purifying 
the  air.  Ventilation  purifies  by  furnishing  pure  air 
which  displaces  the  foul  air;  absorbents  by  attracting 
the  moisture,  and  with  it  the  impurities  of  the  storage 
room ;  but  where  ventilation  is  largely  for  the  purpose 
of  forcing  out  the  permanent  gases  or  impurities 
which  have  little  affinity  for  moisture,  absorbents  are 
for  the  purpose  of  taking  up  the  moisture  and  the 
germs  and  impurities  which  are  absorbed  by  it. 

Active  absorbents  can  be  made  to  perform  duty  in  Prof.  Nice's 

.   .  .  .  .     .  ....  system  which 

absorbing  the  moisture  which  is  usually  condensed  on  utilizes  an 

.  absorbent. 

the  cooling  coils,  as  illustrated  in  one  style  of  the 
antiquated  overhead  ice  cold  storages.  If  the  writer 
remembers  correctly,  the  system  is  called  Prof. 
Nice's  system.  In  this  system  the  ice  is  supported 
above  a  water  tight  sheet  iron  floor  which  forms  the 
ceiling  of  the  storage  room,  the  air  of  the  room  being 
cooled  merely  by  contact  with  this  cold  metal  surface, 
which  is  cooled  by  the  ice  above.  The  moisture 
given  off  by  the  eggs  in  storage,  and  that  resulting 
from  air  leakage  was  taken  up  by  an  absorbent, 
chloride  of  calcium  being  the  chemical  mostly  in 
use  for  this  purpose.  It  was  applied  by  suspend- 
ing it  in  pans  at  the  ceiling  of  the  room,  or  in 
some  cases  on  the  floor  under  the  goods.  Prof. 
Nice's  system  gave  good  results  years  ago  in  com- 
petition with  the  Jackson,  Dexter,  McCrea,  Stevens, 
etc.,  systems  of  overhead  ice  cold  storage,  which  low 

71 


72 


EGGS    IN    COLD   STORAGE. 


Queries 
relating-  to 
absorbents. 


Whitewash  a 
good  wall 
coating-. 


temperatures,  and  the  improved  systems  of  air  cir- 
culation now  in  use  have  rendered  obsolete  to  a  greater 
or  less  extent.  Mention  is  made  of  this  system,  not 
as  recommending-  it,  but  to  show  the  possibilities  of 
absorbents  in  drying-  and  purifying-  egg  rooms. 

The  letter  of  inquiry  sent  out  by  the  writer  con- 
tained three  questions  referring  to  absorbents,  writ- 
ten with  an  idea  of  ascertaining-  the  coating-  used  for 
the  walls  of  a  storag-e  to  the  greatest  extent;  what  ab- 
sorbent was  the  favorite,  and  in  what  manner  applied. 
The  questions  are  as  follows : 

I.  Do  you  use  an  absorbent  or   purifier   in    your 
egg  rooms? 

II.  In  what  way  do  you  use  or  apply  them? 

III.  Do  you  paint  or  whitewash?     What  kind  and 
how  often  applied  ? 

The  most  common  wall  coating  in  use  for  egg 
rooms  is  plain  every-day  whitewash,  in  various  pro- 
portions of  lime  and  salt.  Several  recommend  one 
part  of  lime  and  one  of  salt.  This  makes  a  very 
good  whitewash,  giving  a  firm,  hard  surface,  but  un- 
less some  method  of  blowing  warm,  dry  air  through 
the  rooms  is  feasible,  it  will  dry  very  slowly,  which 
is  likely  to  cause  it  to  have  a  mottled  appearance 
instead  of  the  pure  white  which  gives  a  storage  room 
such  an  attractive  appearance.  A  better  proportion 
for  ordinary  cold  storage  work  is  two  parts  of  lime 
and  one  of  salt.  This  mixture  will  dry  faster,  and 
will  give  a  white  surface  which  will  not  easily  rub  or 
flake  off.  There  are  many  formulas  for  good  white- 
wash, some  of  them  so  complicated  as  to  be  impracti- 
cable; but  plain  lime  and  salt,  with  perhaps  the  addi- 
tion of  a  little  Portland  cement,  will  be  good  enough 
for  our  purpose. 

This  last  formula  would  then  be  six  parts  white 
lime,  three  parts  salt,  one  part  Portland  cement.  In 
preparing  this  wash,  proceed  as  follows:  Slake  the 
quicklime  by  pouring  on  boiling  water,  stirring 


EGGS    IN   COLD    STORAGE.  73 

thoroughly   during-  the   process.     A  half  bushel  ofThebest 

formula  for 

lime  is  all  that  can  be  handled  easily.  Pour  on  only  whitewash. 
a  little  water  at  first,  adding-  more  as  the  mixture 
thickens,  and  do  not  allow  the  lime  to  become  dry,  or 
it  will  "burn"  and  become  lumpy.  When  the  lime  is 
thoroug-hly  slaked  and  reduced  to  the  consistency  of 
cream,  add  the  salt  while  the  mixture  is  still  hot — the 
salt  will  dissolve  better — adding-  more  water  as  is 
necessary  to  keep  it  to  the  proper  consistency.  The 
Portland  cement  should  be  added  only  to  each  pail- 
ful as  used,  as  it  sets  if  allowed  to  stand,  and  does 
not  retain  its  tenacity.  A  good  sized  handful  to  each 
pailful  of  the  wash  is  about  rig-ht.  By  the  addition  of 
a  teaspoonful  of  ultramarine  blue  to  each  pailful,  the 
brown  effect  resulting-  from  the  addition  of  the  cement 
will  be  neutralized. 

Storag-e    rooms    should    be  whitewashed    during-  whitewashing- 

0  storage  rooms. 

cool,  dry  weather,  with  the  doors- open,  or  warm,  dry 
air  from  a  steam  coil  should  be  circulated  throug-h 
the  room.  This  is  quite  a  simple  matter  where  a 
house  is  equipped  with  forced  circulation.  Cover  the 
walls,  ceiling-  and  floor  with  a  coat  of  whitewash 
each  spring-,  and  allow  ample  time  for  the  rooms  to 
air  and  dry  out  before  goods  are  placed  in  them.  If 
whitewash  is  to  have  a  nice  white  appearance  it  must 
not  be  too  long-  in  drying-;  on  the  other  hand,  if  dried 
too  quickly  it  will  flake  or  cleave  off  more  readily. 
The  quickest  method  of  applying  whitewash  is  with 
a  compressed  air  spray.  It  will  make  a  fair  job,  and 
is  done  much  quicker  than  by  hand. 

The  cold  water  paints,  which  are  now  quite  com- cold  water 

j  .    r  paint. 

mon  under  various  names,  are  good  for  many  places 
where  whitewash  will  not  do,  as  on  doors  and  in  the 
corridors,  or  wherever  the  clothing-  may  come  in  con- 
tact with  the  woodwork,  or  where  a  product  is  handled 
which  may  be  injured  by  the  flaking  off  of  whitewash. 
Whitewash  will  generally  rub  or  flake  off  to  some 
extent,  but  the  best  of  these  cold  water  paints  are 


74 


EGGS    IN    COLD   STORAGE. 


Shellac  for 
wall  coating. 


Lime  as  an 

absorbent  of 
moisture  and 
impurities. 


nearly  as  impervious  as  so  much  oil  paint,  and  quite 
valuable  for  nearly  all  interior  and  some  exterior 
work.  Many  houses  use  nothing  else  for  their  refrig- 
erator rooms,  but  the  expense  is  not  warranted,  as 
whitewash  will  do  equally  well  in  most  places.  It  is 
a  good  idea  to  keep  some  of  this  cold  water  paint  on 
hand,  and  apply  it  at  intervals  to  doors,  etc.,  when 
they  become  soiled  by  handling.  This  is  much  better 
than  to  paint  doors  some  dark  color  so  they  will  not 
show  soil — nothing  compares  with  a  pure  white — and 
oil  paint  has  no  place  about  a  storage  room. 

Shellac  is  an  old  stand-by  finish  for  refrigerator 
rooms,  and  if  selected  ceiling  is  used,  it  makes  a  very 
neat  piece  of  work,  as  it  brings  out  the  natural  grain 
of  the  wood,  than  which  there  is  no  more  beautiful 
finish.  The  surface  scratches  easily  and  will  look 
mussy  unless  renewed  frequently,  but  there  is  no 
serious  objection  to  shellac  (barring  the  expense),  as 
it  is  strictly  odorless  and  wraterproof.  It  has  no  puri- 
fying or  disinfectant  properties  like  lime  and  salt 
whitewash,  in  appearance  is  very  little  superior,  and 
the  much  increased  expense  makes  it  very  little  used 
at  present.  Many  other  preparations  are  in  use 
under  various  names,  but  whitewash  is  as  good  as  any 
of  them,  with  the  exception  previously  noted. 

The  two  chemical  absorbents  in  general  use  for 
taking  up  moisture  and  the  impurities  from  cold 
storage  rooms  are  chloride  of  calcium  and  lime 
(either  unslaked  or  air  slaked,  or  in  the  form  of 
whitewash,  as  before  mentioned.)  Occasionally 
waste  bittern  from  salt  works  is  used,  but  the  active 
principle  of  bittern  is  chloride  of  calcium.  Ordinary 
quicklime  has  the  property  of  absorbing  moisture  and 
impure  gases  from  the  air,  and  is  used  in  very  much 
the  same  way  as  chloride  of  calcium;  that  is,  it  is 
placed  around  the  room  on  trays  or  pans.  Lime, 
however,  has  very  little  capacity  for  moisture  as  com- 
pared with  chloride  of  calcium,  and  when  exposed  to 


EGGS    IN   COLD   STORAGE.  75 

the  air  it  will  simply  air  slake,  which  means  that  it 
will  absorb  moisture  enough  from  the  air  to  disinte- 
grate into  the  form  of  a  powder.  Lime  in  this  form  is 
known  as  air  slaked  lime,  and  is  used  to  a  large  ex- 
tent in  egg-  rooms.  Air  slaked  lime  as  it  comes  from 
the  lime  house  will  absorb  very  little  moisture,  but  it 
gives  off  minute  particles  of  lime  which  have  a  good 
effect  in  preventing  the  growth  of  fungus,  which  we 
have  already  fully  discussed.  Air  slaked  lime  is 
usually  applied  by  spreading  on  the  floor  of  the  room, 
between  the  2X4's  (which  are  used  at  the  bottom  of 
each  pile  of  eggs),  to  the  depth  of  an  inch  or  more. 
This  must  necessarily  be  done  when  the  eggs  are 
piled,  and  consequently  its  efficiency  is  very  low 
when  the  cool  weather  of  fall  comes.  This  defect 
has,  been  overcome  by  scattering  fresh  air  slaked 
lime  through  the  rooms  so  as  to  create  a  cloud  of  lime 
dust,  but  this  is  objected  to  because  it  musses  up  the 
cases.  A  better  way  of  using  lime  is  in  the  lump 
form — quicklime — which  can  be  placed  around  the  top 
of  the  room  in  trays  or  pans  and  renewed  from  time 
to  time  through  the  season. 

Chloride  of  calcium  is  the  most  vigorous  absorb- 
ent  (or  drier,  as  it  is  called)  which  we  are  discussing.  absorbent- 
It  is  the  same  salt  of  the  metal  calcium  as  common 
salt  (chloride  of  sodium)  is  of  the  metal  sodium.  Both 
have  a  strong  affinity  for  water,  but  chloride  of  cal- 
cium is  much  the  more  energetic  of  the  two.  Where, 
in  a  moist  air,  common  salt  simply  attracts  enough 
moisture  to  become  damp,  chloride  of  calcium  will 
absorb  enough  water  to  lose  its  solid  form  entirely, 
uniting  with-the  moisture  of  the  air  to  form  a  solution 
or  brine.  The  strong  affinity  of  this  salt  for  water 
has  been  utilized  for  the  purpose  of  drying  and  puri- 
fying refrigerator  rooms,  and  in  this  capacity  has 
been  a  general  favorite  for  years.  The  most  primi- 
tive method  of  applying  it  is  to  place  it  in  a  simple 
iron  pan,  allowing  the  brine  to  run  off  into  a  pail  as 


76  EGGS    IN    COLD   STORAGE. 

fast  as  formed.  A  better  way  is  to  support  the  cal- 
cium on  a  screen  of  galvanized  wire,  with  a  galvanized 
pan  below  for  catching-  the  brine.  This  allows  of  a 
free  circulation  of  air  around  the  calcium.  This 
apparatus  should  be  suspended  near  the  ceiling  of  the 
room,  one  end  slightly  higher,  to  allow  the  brine  to 
run  off  into  a  galvanized  iron  pail,  supported  at  the  low 
end  of  the  pan.  Galvanized  iron  is  specified  because 
black  iron  rusts  badly  when  exposed  to  the  air. 

^  st^  better  way  of  applying  chloride  of  calcium, 
~  wni°n  makes  the  calcium  do  two  separate  and  distinct 
duties,  is  a  method  recently  designed  by  the  writer. 
It  has  proven  itself  especially  valuable  for  use  in 
rooms  where  the  air  is  circulated  by  mechanical 
means,  and  in  which  the  air  is  cooled  by  passing  over 
brine  pipes,  through  which  the  brine  is  circulating  at 
a  comparatively  high  temperature.  If  low  brine  tem- 
peratures are  used  in  combination  with  the  device 
about  to  be  described,  the  tendency  may  be  to  dry  the 
air  to  such  an  extent  as  to  be  detrimental,  and  ample 
pipe  surface  must  be  provided  and  the  quantity  of 
brine  flowing  through  pipes  reduced  so  that  no  ex- 
cessive drying  effect  will  take  place.  The  device 
consists  simply  of  supporting  a  quantity  of  chloride 
of  calcium  above  the  cooling  coils,  so  that  the  brine, 
resulting  from  the  absorption  of  moisture  by  the  cal- 
cium, will  trickle  down  over  the  pipes.  This  effect- 
ually prevents  any  formation  of  frost  on  the  pipes, 
and  therefore  keeps  them  at  their  maximum  efficiency 
at  all  times.  The  air,  in  passing  over  the  brine 
moistened  surface  of  the  coils  is  purified,  and  as  the 
brine,  after  falling  to  the  floor  of  the  coil  room,  goes 
to  the  sewer,  no  contamination  can  take  place. 

Do  not  in  any  method  of  using  chloride  of  calcium 
evaporate  the  water  from  the  brine  and  use  the  salt 
over  again.  The  impurities  will  stay  in  the  salt 
to  a  large  extent,  which  is  quite  harmful,  and  the 
calcium  has  at  least  lost  its  value  as  a  purifier,  to  a 


EGGS    IN   COLD   STORAGE.  77 

large  extent.     The    quantity    of   calcium   necessary  Quantity  of 

j  ,,  ,.,.  .   -  ,  .    ,      .,     .  ,  J  chloride  of  cal- 

depends  on  the  conditions   under  which  it  is  to  becium necessary, 

used,  but  in  any  case  it  is  safe  to  use  much  more  than 

the  writer  saw  in  use  in  an  eastern  house  recently. 

A  room  about  30X50  and  about   fourteen  feet  high 

had   the   refrigerant  shut  off,  and  the  room  was  in 

rather  bad  condition  as  to  moisture,  etc.     In  each  end 

of  the  room  a  pail  was  placed,  on  which  rested  a  wire 

screen,  with  perhaps  ten  or  fifteen  pounds  of  chloride 

of  calcium  on  it.     Electric  fans  were  playing  on  the 

calcium,   which   was   doing  its   best,    but  it  seemed 

"like  trying  to  dip  the  sea  dry  with  a  clam  shell." 

This  room  should  have  had  at  least  two  drums  (about 

1,200  pounds)  at  work  in  it  to  do  it  justice. 


CHAPTER  VI. 


Experiments 
proving1  that 
eggs  must 
evaporate. 


PACKAGK. 

EGGS  are  continually  giving-  off  moisture  from 
the  time  they  are  first  dropped  by  the  hen  until 
they  disintegrate,  unless  sealed  from  contact  with  the 
air,  and  we  can  therefore  never  hope  to  keep  them  in 
cold  storage  for  several  months  without  their  losing 
some  weight  by  evaporation.  To  prove  that  eggs 
must  evaporate,  the  following  experiment  was  tried 
by  the  writer  in  his  early  experience:  An  ordinary 
30-dozen  egg  case  was  lined  with  tin,  with  all  joints 
carefully  soldered.  The  eggs  were  then  placed  in 
the  fillers  in  the  tin  lined  case  in  the  usual  way,  and 
an  air  tight  tin  cover  soldered  on,  forming  a  hermeti- 
cally sealed  package.  After  about  sixty  days'  stay 
in  an  ordinary  refrigerator  the  tins  were  unsoldered. 
The  result  noted  was  peculiar  and  startling.  The 
inside  of  the  tins  was  dripping  wet,  and  very  foul 
smelling,  and  the  eggs  were  all  rotten.  This  same 
experiment-was  tried  by  a  friend,  working  independ- 
ently and  without  knowledge  of  the  writer's  experi- 
ment. He  used  an  ordinary  fruit  jar,  with  screw  top 
fitting  onto  a  rubber  ring.  His  results  were  similar. 
In  addition  this  gentleman  packed  some  eggs  in  flour 
in  a  fruit  jar,  otherwise  under  the  same  conditions 
as  the  other  experiment.  The  eggs  packed  in  this  way 
were  all  found  to  be  in  good  condition  when  the  jar 
was  opened,  as  the  moist  evaporation  from  the  eggs 
had  been  taken  up  by  the  flour.  These  experiments 
prove  beyond  a  doubt  that  an  egg  must  evaporate 
continually,  and  they  prove  further  that  the  eggs 
must  be  surrounded  by  some  medium  which  will 
absorb  this  evaporation. 

We  have  noted  in  the  chapter  on  "Circulation," 
how  the  air  is  best  circulated  so  as  to  remove  the 

78 


EGGS    IN   COLD   STORAGE.  79 

moisture  and  impure  gases  from  the  vicinity  of  the 
eggs.  This  must  be  done,  otherwise  the  fillers  and 
package  containing-  the  eggs  would  shortly  be  in  as 
bad  condition  as  the  fillers  in  the  experiment  just 
mentioned.  The  theory  and  explanation  of  the  other 
conditions  in  the  storage  room  necessary  for  success- 
ful egg-  refrig-eration  have  also  been  taken  up  under 
the  various  heads.  We  will  now  look  into  the  require- 
ments of  the  packag-e  containing  the  eggs  while  in 
cold  storage. 

The  questions  contained  in  the  letter  of  inquirvQueries 

J  relating-  to 

relating  to  the  egg  package  are  as  follows:  package. 

1.  What  egg  package  have  you  found  to  turn  out 
the  sweetest  eggs? 

2.  Have  you  used  any  kind  of  ventilated  egg  case, 
and  with  what  results? 

3.  Have  you  ever  used  open  trays  or  racks,  and 
with  what  results? 

As  many  different  people  have  experimented  with  various  woods 

.  m  use  for  cases. 

different  packages,  hoping  to  get  something  which 
would  turn  out  perfectly  sweet  eggs,  with  little  evap- 
oration, the  replies  received  to  the  questions  relating 
to  packages  are  interesting,  and  many  contained  in- 
formation valuable  as  data.  The  favorite  package  is 
the  ordinary  30-dozeii  egg  case,  made  of  white- 
wood,  using  the  so  called  odorless  fillers.  The  term 
whitewood  is  usually  meant  to  include  either  poplar, 
cotton  wood  or  bass  wood,  but  two  or  three  other  vari- 
eties of  wood,  not  so  well  known,  are  designated  as 
whitewood.  Basswood  is  by  some  not  placed  in  the 
whitewood  list,  but  the  best  authority  known  to  the 
writer  says  that  basswood  is  as  properly  a  whitewood 
as  poplar  or  southern  whitewood.  Poplar  and  cotton- 
wood  are  most  in  use  for  storage  purposes,  and  many 
insist  that  basswood  is  objectionable  because  of  its 
liability  to  ferment  or  sour  and  cause  tainted  or  musty 
eggs.  All  kinds  of  cases  have  been  in  storage  in  the 
house  operated  by  the  writer,  and  if  all  were  thor- 


80  EGGS    IN    COLD   STORAGE. 

oughly  dry,  no  difference  could  be  noted  in  the  carry- 
ing- qualities  of  the  different  kinds  of  whitewood,  and 
the  preference  has  been  for  well  seasoned  basswood 
cases.  It  may  be  that  basswood  is  more  likely  to  sour 
and  affect  the  eggs  than  poplar  or  cottonwood,  but  it 
is  always  advisable  to  get  stock  for  egg  cases  in  the 
fall  and  have  them  nailed  up  during-  the  winter,  allow- 
ing- two  or  three  months  for  the  cases  to  season  before 
the  opening  of  the  egg  storing  term.  Some  have  dry 
kilns  for  cases,  but  a  naturally  seasoned  case  is  to  be 
preferred,  as  then  it  has  a  chance  to  deodorize  as  well 
as  dry  out.  In  some  localities  other  woods  are  used 
for  egg  cases.  Ash,  maple,  hemlock  and  spruce  have 
been  used  for  storage  cases,  generally  because  they 
are  cheaper  than  whitewood  in  that  locality.  Any 
strong  scented  wood  like  pine  will  not  do  because  of 
the  flavor  imparted  to  the  eggs. 

The  pasteboard  frames  and  the  horizontal  divid- 
ing or  separating  boards  which  form  for  each  egg  an 
individual  cell  in  the  case  are  usually  spoken  of  as 
fillers.  For  years  only  one  grade  of  these  was  made 
— those  of  ordinary  strawboard.  When  moistened  by 
the  evaporation  from  the  eggs  this  material  has  a  pe- 
culiar rank  odor,  which  was  taken  up  to  some  extent 
by  the  eggs  if  they  were  allowed  to  remain  in  the 
fillers  for  several  months.  Much  of  the  flavor  result- 
ing from  a  growth  of  fungus  has  been  laid  to  the  fill- 
ers, and  much  of  the  flavor  resulting  from  fillers  has 
been  laid  to  a  growth  of  fungus  or  must,  but  there  is 
no  question  but  what  strawboard  fillers  are  not  the 
thing  for  cold  storage  use.  Many  kinds  of  fillers  have 
been  tried,  and  many  ideas  suggested  for  the  improve- 
ment of  cold  storage  eggs.  A  white  wood  pulp  filler 
made  its  appearance  some  years  ago,  but  did  not 
come  into  general  use.  After  being  in  storage  a  few 
months,  it  absorbed  moisture  to  such  an  extent  as  to 
be  very  soft,  and  they  were  objectionable  on  this  ac- 
count. A  good  manila  odorless  is  now  on  the  market 


EGGS    IN    COLD   STORAGE.  81 

which  is  giving-  good  satisfaction  where  tried.  Ordi- 
nary strawboard  fillers  have  been  coated  with  various 
preparations,  shellac,  paraffine,  whitewash,  etc.  Any 
substance  in  the  nature  of  waterproofing-  might  better 
be  left  off  for  the  reason,  as  we  have  seen,  that  eggs 
must  evaporate,  and  a  waterproof  filler  would  hold  the 
moisture  and  not  allow  it  to  escape  into  the  air  of  the 
room.  It  is  essential  to  the  well  being  of  an  egg  that 
it  should  evaporate,  as  proven  by  the  experiments  in 
hermetically  sealing,  before  described.  Many  have 
gone  to  the  expense  of  transferring  the  eggs  into  dry 
fillers  in  the  middle  of  the  season.  One  season  of  this 
was  enough  for  the  writer.  A  better  way  is  to  de- 
crease the  humidity  of  the  room  as  the  fillers  become 
more  and  more  loaded  with  moisture.  The  humidity 
may  be  decreased  by  the  use  of  absorbents  or  by  ven- 
tilation, as  already  discussed  in  their  proper  places. 
Fillers  made  of  thin  wood  have  been  used  in  years 
gone  by  with  fair  success,  but  tlieir  manufacture  has 
now  been  entirely  discontinued.  They  were  made  of 
maple,  shaved  very  thin,  and  were  a  prime  filler  so 
far  as  odor  was  concerned,  but  in  cold  storage  the 
frames  warp  badly,  and  the  time  and  eggs  wasted  in 
getting  the  eggs  out  of  the  fillers  was  a  serious  item 
against  their  use.  As  a  shipping  filler  they  were  also 
a  failure  because  of  the  excessive  breakage.  Some 
years  ago  an  eastern  company  began  the  manufacture 
of  what  is  known  as  the  odorless  fillers.  These  fill- 
ers are  light  brown  or  buff  in  color,  and  from  the  best 
information  the  writer  can  obtain,  are  composed 
largely  of  scrap  paper  stock,  with  some  long  fiber  like 
manila  added  for  strength.  In  the  manufacture  the  odorless 
stock  is  treated  to  a  thorough  washing  and  deodoriz- 
ing process,  and  the  result  is  a  filler  with  very  little 
odor.  Eggs  put  up  in  these  so  called  odorless  fillers 
and  subjected  to  the  same  conditions  as  a  similar 
grade  of  eggs  packed  in  common  strawboard  fillers, 
generally  come  out  of  cold  storage  markedly  superior. 


82  EGGS    IN    COLD   STORAGE. 

A  number  of  imitations  of  the  original  odorless  filler 
are  now  on  the  market,  some  of  them  almost  if  not 
quite  the  equal  of  the  original.  Another  filler  which 
has  given  good  results  is  the  fiber  filler,  which  is  made 
from  a  material  similar  to  the  now  well  known  fiber 
ware.  They  have  very  little  odor,  and  remain  hard 
and  firm  while  in  cold  storage.  A  new  odorless  filler 
made  from  pure  spruce  pulp  has  been  put  on  the 
market  this  season.  This  is  a  beautiful  appearing 
filler,  and  unless  appearances  and  the  ordinary  tests 
are  deceptive  will  make  its  mark  after  a  trial  of  a  year 
in  cold  storage  to  prove  what  it  can  do.  A  ventilated 
filler  made  by  a  well  known  creamery  supply  house, 
has  been  suggested  as  an  ideal  filler  for  cold  storage, 
but  they  are  so  poor  mechanically  that  they  are  not 
to  be  thought  of.  The  material  cut  away  to  form 
the  air  circulation  space  weakens  the  structure  of  the 
filler  to  such  an  extent  as  to  make  it  dangerous  as  a 
shipping  filler.  Whatever  filler  is  used,  it  should  fit 
the  cases,  not  crowding  in,  nor  still  so  loose  as  to 
shake.  If  this  point  is  looked  after  much  breakage 
and  consequent  poor  results  from  storage  in  the  cold 
room  may  be  avoided. * 

ventilated  Many  styles  of   ventilated   egg  cases   have   been 

tight  cases.  placed  on  the  market  in  years  past,  but  very  few  or 
none  survive  the  test  of  time.  A  ventilated  case,  made 
by  having  the  sides  cut  an  inch  narrower  than  the 
ends,  has  come  into  use,  especially  in  one  large  eastern 
city.  Making  the  sides  narrower  forms  a  space  of 
half  an  inch  on  both  sides  of  case  at  top  and  bottom, 
for  the  ready  access  of  air  to  the  interior  of  the  case. 
This  case  is  of  very  simple  construction,  and  efficient 
in  allowing  a  free  circulation  of  air  into  the  case. 
Others,  however,  prefer  a  case  with  sides  in  two 
pieces,  claiming  that  the  cracks  will  allow  enough  air 
circulation.  Still  others  prefer  the  shaved  or  veneered 
cases  with  solid  sides  and  bottom,  claiming  that  this 
kind  of  a  case  will  prevent  excessive  evaporation 


EGGS    IN    COLD   STORAGE.  83 

from  the  egg's.  As  pointed  out  elsewhere  in  these 
articles,  humidity  and  circulation  have  much  to  do 
with  the  evaporation  from  eggs;  in  fact,  are  more  of 
a  ruling  factor  than  the  package,  although  the  package 
necessarily  has  much  to  do  with  it.  A  tight  package 
will  allow  of  less  evaporation  than  an  open  one.  In  a 
very  dry  room  with  a  vigorous  circulation  a  moder- 
ately tight  package  is  the  thing,  but  in  a  compara- 
tively moist  room  with  poor  circulation  the  more  open 
the  package  the  better. 

An  appreciation  of  the  poor  circulation  and  damp  storing  eggs  m 

r  r  f  trays  or  racks. 

air  of  the  overhead  ice  systems  has  caused  many  of 
their  operators  to  resort  to  the  use  of  open  trays  or 
racks  for  the  storage  of  eggs.  Very  palatable  eggs 
have  been  turned  out  in  this  way,  but  the  use  of  trays 
in  any  ammonia  or  brine  cooled  room  would  lead  to 
very  excessive  shrinkage  of  the  eggs  and  consequent 
heavy  loss  in  candling.  On  a  commercial  scale,  too, 
the  storing  of  eggs  in  trays  is  hardly  practicable,  as 
it  increases  the  risk  of  breakage  immensely,  and  the 
eggs  must  be  transferred  from  the  cases  when  re- 
ceived at  the  storage  house,  and  back  into  cases  again 
when  shipped,  involving  much  labor,  and  perhaps  loss 
of  valuable  time  at  some  stages  of  the  market.  In  any 
but  a  very  moist  room,  eggs  stored  in  open  trays,  in 
bulk,  will  lose  much  from  evaporation,  and  the  loss 
will  be  proportionately  higher  than  on  an  equal  grade 
of  eggs  stored  in  ordinary  cases  and  fillers.  The  ad- 
vantage of  trays,  if  any,  for  some  houses,  is  that  con- 
tamination from  fillers  is  avoided,  and  about  40  per 
cent  more  eggs  can  be  stored  in  a  given  space.  The 
eggs  are,  however,  more  liable  to  must  as  a  result  of 
moisture  condensing  on  their  surface  with  change  of 
temperature,  or  on  the  introduction  of  warm  goods 
into  the  storage  room. 

The  material  used  for  forming  a  cushion  in  the 
case  on  top  and  bottom  of  the  fillers  to  protect  the 
eggs  from  contact  with  the  case,  and  so  that  they  will 


84 


KGGS    IN    COLD   STORAGE. 


Excelsior 

TS. 

cork  shaving-s 
for  cushion. 


Packing-  eggs 
in  oats. 


carry  in  shipping-,  is  generally  either  excelsior,  which 
is  finely  shaved  wood,  usually  basswood,  or  the  chips 
made  in  the  manufacture  of  corks,  known  as  cork 
shaving's.  The  big-  cold  storages  recommend  cork 
now  in  preference  to  the  best  excelsior.  Here  again 
comes  a  question  of  dryness.  If  the  excelsior  has 
been  in  stock  for  a  year  and  stored  in  a  dry  place  it  is 
to  be  preferred  to  cork  shavings,  otherwise  cork  is  the 
best,  because  we  know  cork  is  always  dry.  Cork 
makes  a  very  poor  cushion  as  compared  to  excelsior; 
it  is  liable  to  shift  in  the  case,  leaving  one  side  without 
protection.  As  a  matter  of  cost  too,  cork  is  much 
more  expensive  than  excelsior.  A  company  known 
to  the  writer  manufacture  a  beautiful  grade  of  bass- 
wood  excelsior,  which  is  always  fairly  dry  when  re- 
ceived, and  makes  as  fine  a  cushion  for  protecting  the 
eggs  as  can  be  desired.  If  people  want  cork  in 
their  cases  they  can  have  it  by  paying  the  price,  but 
dry,  seasoned,  fine-  basswood  excelsior  is  better,  for 
reasons  stated. 

Eggs  have  been  packed  in  oats  for  years,  but  the 
practice  has  gradually  fallen  off,  as  eggs  stored  in 
cases  from  the  best  cold  storage  houses  have  been  im- 
proved in  quality  from  year  to  year.  Oats,  if  dry, 
will  absorb  moisture  from  the  egg  quite  rapidly,  and 
are  objectionable  on  this  account.  If  the  oats  are  not 
dry  the  germs  of  mold  are  developed  rapidly,  and  as 
the  moisture  is  given  off  by  the  eggs,  the  mold  will 
grow,  causing  the  eggs  to  become  "musty."  There- 
fore the  main  difficulty  in  using  oats  as  packing  for 
eggs  in  cold  storage  is  to  have  them  at  the  correct  de- 
gree of  dryness.  It  is  almost  impossible  to  have  them 
in  the  same  condition  at  all  times.  Oats  have  also  been 
used  in  cases  inside  the  fillers,  that  is,  the  layers  of 
eggs  are  first  put  into  the  filler;  then  the  oats  are  sifted 
into  the  spaces  around  the  eggs  flush  with  the  top  of 
the  filler.  This  is  repeated  through  the  whole  case; 
all  the  space  in  the  case  not  occupied  by  the  eggs 


EGGS    IN   COLD   STORAGE.  85 

being-  filled  with  oats,  excepting-  the  small  space  taken 
by  the  fillers  themselves,  the  object  being-,  of  course, 
to  prevent  the  "fillers  taste." 

At  intervals  we  read  of  some  method  of  preserving-  complicated 

~  and  obsolete 

eg-g-s,    which   is   said  to  be   sure,  to  supersede  or di-  methods  of  pre- 
serving- eg-g-s. 

nary  cold  storag-e  for  the  good  keeping-  of  egg-s.  A 
scheme  was  tried  on  a  larg-e  scale  somewhere  across 
the  water,  in  which  the  eg-g-s  were  suspended  in  racks 
in  a  cold  room — the  racks  being-  turned  at  regular  in- 
tervals by  automatic  machinery  to  keep  the  eg-g-s  from 
spoiling-,  that  is,  to  keep  the  yolk  from  attaching-  to 
the  shell.  A  low  temperature  will  prevent  this,  as 
pointed  out  in  the  chapter  on  temperature,  and  why 
a  man  should  waste  good  energy  inventing  such  a  ma- 
chine is  passing  all  comprehension.  The  quantity  of 
various  chemical  preparations  manufactured  and  sold 
for  egg  pickling  or  preserving  is  even  now  quite  large, 
but  the  high  class  stock  now  turned  out  by  the  best 
equipped  cold  storage  houses  has  made  any  other 
method  of  preserving  eggs  at  the  present  day  almost 
entirely  obsolete. 


CHAPTER  VII. 

REMARKS. 

some  "dont's"  ^  I  ^HERE  is  a  long  string-  of  "don'ts  "  in  regard  to 
SSHJtSf'  1  packing-, handling-  and  storing-  egg's  which  might 
be  put  down,  but  the  writer  will  be  content  with  a  few 
of  the  simpler  and  most  useful  ones.  To  start  with, 
don't  store  very  dirty,  stained,  cracked,  small  or  bad 
appearing  eggs  of  any  description.  Have  your  grade 
as  uniform  as  possible.  The  culled  eggs  will  usually 
bring  within  two  cents  of  the  market  price,  and  it 
pays  better  to  let  them  go  at  a  loss  rather  than  try  to 
store  them.  Don't  use  fillers  and  cases  the  second 
time;  they  are  more  likely  to  cause  musty  eggs  than 
new  ones.  Don't  ship  eggs  in  cold  cars,  or  set  eggs 
which  are  intended  for  storage  in  ice  boxes.  In  ship- 
ping eggs  from  the  producing  section  to  the  storage 
house  in  refrigerator  cars,  no  ice  should  be  put  in  the 
bunkers,  because  if  the  eggs  are  cooled  down  and  ar- 
rive at  their  destination  during  warm  or  humid 
weather  they  will  collect  moisture  or  "sweat,"  and  an 
incipient  growth  of  mold  will  result.  Don't  use  heavy 
strawboard  fillers  for  storing  eggs.  If  "the  best  way 
to  improve  on  a  good  thing  is  to  have  more  of  it,"  then 
the  best  way  to  improve  on  a  poor  thing  is  to  have  less 
of  it;  and  if  strawboard  fillers  are  objectionable,  then 
the  thinner  they  are  the  better,  because  less  of  the 
material  is  present  to  flavor  the  eggs.  Further,  the 
thin  board  fillers  are  more  porous,  and  allow  of  a  freer 
circulation  of  air  around  the  egg.  As  already  stated, 
odorless  fillers  are  better  than  any  strawboard  fillers. 
Don'tlise  freshly  cut  excelsior.  It  should  be  stored 
in  a  dry  place  at  least  six  months.  Use  no  other  kind 
but  basswood  or  whitewood.  Don't  store  your  cases, 
fillers  or  excelsior  in  a  basement  or  any  damp  place. 
Don't  run  warm  goods  into  a  room  containing  goods 

86 


KGGS    IN   COLD   STORAGE.  87 

already  cooled  when  it  can  be  avoided.  For  this  rea- 
son very  large  rooms  are  not  to  be  desired.  A  small 
room  may  be  quickly  filled  with  goods  and  closed  until 
goods  begin  to  go  out  in  the  fall.  If  a  large  room  is 
used  it  may  require  several  weeks  to  fill  completely, 
during  which  time  the  fluctuation  of  temperature  is 
at  times  excessive,  causing  condensation  on  the  goods, 
which  will  propagate  must  quickly. 

To  illustrate:  We  will  suppose  the  egg  room  partly  Don't  put 

r  J   warm  egg's  into 

filled  with  goods  cooled  to  a  temperature  of  30°  F.  Sev-acoldroom 

1  along  with  eggs 

eral  cars  of  eggs  at  a  temperature  of,  say,  70°  F.  are  run  already  cooled. 
into  the  same  room.  The  new  arrivals,  in  cooling  to 
the  low  temperature,  give  off  large  quantities  of  vapor 
from  cases,  fillers  and  the  eggs  themselves,  the  vapor 
condensing,  of  course,  on  any  object  in  the  room  which 
is  below  the  dew  point  of  the  air  from  which  the  warm 
goods  came.  This  may  seem  like  a  finely  spun  theory, 
but  the  writer  has  had  some  experience  which  amply 
justifies  this  explanation.  That  the  moist  vapor  given 
oif  by  the  warm  goods  does  not  show  in  the  form  of 
beads  of  water,  or  fog,  or  steam,  is  no  proof  that  it 
does  not  exist.  If  the  extremes  of  temperature  are 
as  great  as  25°  F.  condensation  will  occur  on  nine 
days  in  ten  during  the  egg  storing  season.  The  goods 
already  in  storage  are  raised  in  temperature  materi- 
ally by  placing  in  warm  goods,  which  is  harmful  to 
some  degree.  The  logical  deduction  from  above 
seems  to  indicate  that  warm  goods  should  not  be 
placed  in  a  room  with  goods  which  have  been  reduced 
to  the  carrying  temperature.  A  separate  room 
should  be  provided  for  this  purpose  near  the  receiv- 
ing room  in  which  the  goods  coming  in  warm  may  be 
cooled  to  very  near  the  temperature  of  permanent 
storage  room.  This  is  a  refinement  which  small 
houses  cannot  afford,  and  which  most  of  the  larger 
ones  do  not  have. 

If  you  wish  to  progress  compare  your  results  with 
those  of  others.   Don't  say:   "My  eggs  are  as  good  as 


88  EGGS    IN   COLD   STORAGE. 

fresh";  test  carefully  from  time  to  time  through  the 
season,  and  compare  quality  with  those  from  other 
houses. 

In  the  foregoing"  articles  I  have  given  my  own  im- 
pressions combined  with  the  data  and  experience  re- 
ceived from  others;  but  I  do  not  care  to  be  held  abso- 
lutely to  any  of  the  statements  made,  and  reserve  the 
right  to  progress  with  the  rest  of  you,  and  do  not 
consider  myself  bound  by  any  hard  and  fast  rule. 

It  should  be  positively  understood  that  a  mere 
theoretical  information  on  this  subject  is  of  only  lim- 
ited assistance;  and  those  who  undertake  new  work 
are  advised  to  put  a  man  in  charge  who  has  had  expe- 
rience with  the  product  which  it  is  proposed  to  handle 
in  storage,  as  well  as  acquaintance  with  the  mechanical 
details  of  the  plant. 


ADVERTISEMENTS 


Testing  Eggs  by  Electric  Light. 

This  picture  is  from  a  photograph  of  a  couple  of  candling-  booths,  designed  by  the 
author  of  "Eggs  in  Cold  Storage."  Each  candler  works  by  herself  in  a  small  room 
closed  on  three  sides  by  matched  stuff,  and  on  the  fourth  or  front  side  by  a  heavy 
curtain  to  keep  out  the  light.  These  curtains  are  seen  pushed  back  in  the  picture,  so 
that  the  interior  of  the  booth  may  be  photographed.  The  white  boxes  in  the  center  of 
the  booths  are  candling  boxes.  They  are  pierced  with  two  holes,  and  have  an  electric 
light  suspended  inside  A  shelf,  showing  in  the  picture,  runs  around  three  sides  of  the 
booth  at  a  convenient  height  above  the  cases,  for  supporting  fillers,  dividing  boards, 
nails,  hatchet,  etc.  The  barrel  is  for  the  litter  of  various  kinds  (old  newspapers,  etc.) 
which  alwaj's  accompany  country  packed  eggs.  The  pail  just  above  the  barrel  is  for 
rotten  eggs.  Cork  shavings  may  be  seen  in  the  box  between  the  two  booths.  The 
advantage  of  each  candler  working  independently  will  be  appreciated  by  all  familiar 
with  the  work.  The  concise  arrangement  of  this  style  booth  makes  a  great  saving  in 
space  as  compared  to  the  ordinary  candling  room. 

MADISON  COOPER, 

Refrigerating  Engineer, 

MINNEAPOLIS,  MINN., 

410  First  St.,  N. 

Designer  of  "The  Cooper  Systems,"  Gravity  Brine  Circulation; 

Positive  Fan  Ventilation  and  Forced  Air  Circulation. 
Plans,  Estimates  and  Personal  Supervision  of  Construction. 

Expert  on  the  Successful  Refrigeration  of  Perishable  Products. 


ADVERTISEMENTS 


NEW  YORK 

OFFICE, 

85    CHAMBERS 

STREET 


LONDON 

OFFICE 

106  HATTON 

GARDEN,  E.  C. 


41    ELIZABETH  STREET 

MAKERS    OF 


thermometers 


FOR    ALL 

REFRIGERATING 
ICE  MAKING  AND 
COLD  STORAGE 

PURPOSES 
THERMOMETER  FOR 

BRINE  TANKS,    PUMPS 

AMMONIA  PIPES 

AND  STILLS 

INSULATED  BRINE  PIPE 

THERMOMETER 
FREE  FROM  FROST 

CERTIFIED  EGG   ROOM 

THERMOMETER,  ETC. 


FIG.  A-L 


uime  for  Refrigerating  Catalogue 


FIG.  31. 


ADVERTISEMENTS 


THE  WHITLOCK  COIL  PIPE  CO 

ELMWOOD,  CONN.,  II.  S.  A. 

Pipe    Coils  of   every  descrip- 
tion— for  all  purposes — made 
of  all  kinds  of    metal,  tubing- 
or  pipe.     Manifolds   and    Re- 
ceivers—  Quarter  Turns   and 
Manufacturers       Return  Bends. 
of... 

Wrought  Iron  Ammonia  Coils 

Dally  capacity,  8,000  to  10,000  ^or  Ice  and  Refrigeration  Machines- 
feet.  Range,  H  to  4-inch  pipe  by  the  latest  improved  process,  from 
or  tube.  First-class  workman-  wrought  iron  pipe  of  the  finest  quality, 
ship,  prompt  Tested  by  hydraulic  or  air  pressure. 

THE  WHITLOCK  COIL  PIPE  CO. 

ELMWOOD,  CONN.,  U.  5.  A. 

Cable  Address,  "Whitlock,"  Hartford 

Directory  Code. 

Telephone  Address,  Elmwood 

Carbonic -Anhydride  System 

ECONOMY    |  SAFETY 


ODORUESS  !SO!S-COI*RO«IVI. 

This  is  the  COMING  ICE  AND  REFRIGERATING  MACHINE  ;  applicable  to  all  com- 
mercial purposes.  Superiorit}'  established  in  numerous  trials.  Uses  a  harmless  but 
most  efficient  gas,  and  is  equipped  with  reliable  safety  devices.  Our  Catalogue  explains 
all  theoretical  and  technical  details.  If  you  are  interested,  write  to 

KROESCHELL  BROS.  ICE  MACHINE  Co, 

29=39  ERIE  STREET,  CHICAGO,  ILL. 


ADVERTISEMENTS 

44  " 


The  Cooper  System 

Forced  Air  Circulation. 


BY  THOSE 

WHO  KNOW. 

F.  R.  NOONAN  &  CO*—  Wholesale  Butter  and  Eggs 
and  Cold  Storage,  Minneapolis,  Minn. 

"We  have  used  your  Forced  Air  Circulation  in  our  Egg-  Rooms  for 
the  past  two  years,  and  are  fully  convinced  that  it  is  the  only  proper 
way  to  carry  eggs  in  cold  storage.'' 


E.  F.  DUDLEY— Wholesale  Butter  and  Eggs, 
Owosso,  Mich. 

"I  consider  your  Forced  Air  Circulation  for  Eg-g-  Rooms  very 
fine.  It  gives  the  rooms  bright,  clear,  fresh-smelling  air  and  very 
even  temperature  ;  much  better  in  this  respect  than  the  more  com- 
mon method  of  simply  taking1  in  fanned  air  at  one  or  two  opening's 
in  a  room — to  say  nothing-  of  the  behind-time  systems  of  natural 
draft."  

PORTLAND  ICE  WORKS  and  PORTLAND  ARTI- 
FICIAL ICE  CO,,  Portland,  Ore. 

"I  placed  eight  registered  thermometers  in  different  locations 
in  this  larg-e  Egg-  Room.  I  never  witnessed  such  a  remarkable, 
even  scale  of  temperatures.  With  your  system  of  Air  Circulation 
there  is  not  a  spot  in  this  room  where  there  is  a  difference  of  one- 
tenth  of  a  degree.  The  temperature  is  easily  controlled.  It  can  be 
placed  at  any  point  desired,  and  held  there  without  risk  of  any 
kind.'' 

W.  E.  HARRIS, 

Sup't  Mechanical  Department. 

MADISON  COOPER,  Designer, 

Minneapolis,  Minn. 


Compressed 


Published  monthly.  Now  in  its  fourth  year.  The  only  periodical  devoted  exclu- 
sively to  this  subject.  It  is  both  theoretical  and  practical,  progressive  and  up-to-date. 
Subscription,  $1.00  a  3rear.  Foreign,  $1.50.  Send  for  sample  copy. 

Compressed  Air>  26  CORTLANDT  ST.,  N.  Y. 


ADVERTISEMENTS 


EUGENE  T.  SKINKLE 

("THE  BOY") 

lice  flftaktri    anb 


IRefrioeratlng  Engineer 

ROOMS   30  AND  32 

177  LA  SALLE  STREET 

CHICAGO,  ILL. 


Plans  and  specifications  for  Ice  Making  and  Refrig- 
erating establishments,  and  consultation  in  relation  to 
buildings,  machinery  and  apparatus,  alterations  and 
repairs. 

IReferences: 

BIRMINGHAM  ICE  FACTORY  CO.,  Birmingham,  Ala. 
CITY  ICE  MANUFACTURING  CO.,  Chicago,  111. 
LITTLE  ROCK  ICE  CO.,  Little  Rock,  Ark. 

EAST  ST.  LOUIS  ICE  AND  COLD  STORAGE  CO.,  E.  St.  Louis,  111. 
KINGSTON  ICE  MAKING  CO.,  Limited,  King-ston,  Jamaica,  West  Indies 
GEO.  CHALLONER'S  SONS  CO.,  Oshkosh,  Wis. 

EL  RENO  ICE  AND  COAL  CO.,  El  Reno,  Okl. 
MONROE  CATERING  CO.,  Chicago,  111. 

KING'S  RESTAURANT,  Chicago,  111. 

AMERICAN  RESTAURANT,  Chicago,  111. 
And  Many  Others. 


Hce  flDafeitiQ  anfc  IRefrigeratiriQ  Supplies 


AD  VKR  TISEMENTS 


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A    MONTHLY   REVIEW   OF   THE    ICE,    ICE   MAKING,  REFRIGERATING.   COLD  STORAGE  AND 

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PUBLISHERS 


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Also  publishers  of  the  following  Standard  Rooks  on  Cold  Storage,  Ice  Making 
and  Refrigeration: 

Gompenft  of  /Ibecbanfcal  IRefrigeration 

By  PROF.  J.  E.  SIEBEL. 

PRICE.  PREPAID.  CLOTH,  $3.00;  MOROCCO.  $3.50. 

The  only  work  treating-  of  all  the  various  branches  of  theoretical  and  applied 
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practical  1lcc  /Rafting  and  IRefruieratuui 

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Ever}7  branch  of  ice  making  and  refrigerating-  is  handled.in  this  work,  with  a  view 
to  setting-  out  the  best  and  most  economical  practice  in  the  construction  and  operation 
of  the  plant. 

Ifnfcicattns  tbe  1Refn0eratin0 

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PRICE.  PREPAID.  CLOTH,  $1.00;  MOROCCO,  $1  50. 

Treats  of  the  application  of  the  indicator  to  the  ammonia  compressor  and  steam 
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and  reading-  and  computing-  indicator  cards. 


ADVERTISEMENTS 

HEADQUARTERS  FOR 


Chloride 
Calcium 


Prime  white,  full  strength,  packed  in  600-pound  iron  drums. 
Representing-  the  largest  output  in  the  country,  we  are  in  condi- 
tion to  name  interesting-  prices  for  car  lots  or  less  quantities. 

PETER  VAN  SCHAACK  &  SONS 

138-140    LAKE  STREET,-CHICAGO. 

ACCURATE  THERMOMETERS. 

Thermometers  bought  from  us  at  one  time  give  the  same  result 

as  thermometers  bought  from  us  at 

any  other  time. 

Prof.  Marvin's  Sling  Psychrometer 

for  the  exact  determination  of  moisture  in  the  air,  is  made 
with  the  utmost  care  and  is  the  best  of   its  class. 

ALL  THERMOMETERS  MADE  BY  US  ARE 
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OBTAINED  WITH   THE 


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FOR   PARTICULARS  ADDRESS 


THE 


CARBONDALE,   PA. 

NEW  YORK   OFFICE,    1012    HAVEMEYER    BUILDING. 


NONPAREIL  CORK 


Che  Ideal 
Insulation 


Sheets  for 
Walls 
Rooms 
Ceilings. 

3- feet 

Sections  for 

Steam,  Brine 

Ammonia 

and 
Water  Pipes 


Ui^b    WOtvK!        says"THEBOY" 

in   his    Practical  Ice  Making  and  Refrigerating, 
page  164, 

"In  the  selection  of  insulating-  substances 
their  power  to  withstand  moisture  plays  an  im- 
portant part  in  most  cases.  In  this  respect  Cork 
is  a  very  desirable  material,"  says  Professor 
J.  E.  SIEBEL  in  his  Compend  of  Mechanical  Refrig- 
eration, page  155. 


The  Nonpareil  Cork  Mfg.  Co. 


28  QUEEN  STREET, 

LONDON,  E*  C,  ENG. 


92  WEST  BROADWAY, 

NEW  YORK,  N.  Y. 


A  D  VKK  TISKMEN  TS 


Tee  and  Refrigerating  machines 


FOR  CREAMERIES  AND 
PRODUCE  DEALERS 


Refrigerating  Machines  are  rapidly  taking  the  place  of 
ice  for  refrigerating  purposes.  A  lower  temperature  can 
be  secured.  The  cold  is  absolutely  dry.  It  will  pay  you  to 
investigate  and  get  estimate  on  plant. 


SIMPLE 
STRONG 
COMPACT 
DURABLE 


ijr 


LARGEST 
EFFICIENCY 
POSSIBLE  BE- 
CAUSE ABSO- 
LUTELY NO 
CLEARANCE 


THE  ONLY  SMALL  MACHINES  OF  DUPLEX  TYPE 

EQUIVALENT  TO  TWO  INDEPENDENT  MACHINES.    ONE 
ALWAYS  IN  RESERVE  AS  PROTECTION   AGAINST 
LOSS    FROM    STOPPAGES   AND    BREAK    DOWNS. 

Small  Plants  from  2  to  10  Coits  Refrigerating  Capacity  Our  Specialty 

Estimates  Cheerfully  and  Promptly  Given. 


Write  for  our  Handsomely  Illustrated  Booklet  named  ''Cold  Making." 


CREAMERY  PACKAGE  MANFG.  Co, 

1,  3  AND  5  WEST  WASHINGTON  STREET 

CHICAGO,  ILL. 


Doo 
and 

THIS  BOOK  IS  DUE  ON  THE  LAST  DATE 
STAMPED  BELOW 

AN     INITIAL    FINE    OF    25     CENTS 

WILL   BE  ASSESSED    FOR    FAILURE  TO    RETURN 
HIS   BOOK  ON   THE  DATE  DUE.     THE  PENALTY 
WILL  INCREASE  TO  SO  CENTS  ON  THE  FOURTH 

OVERDUE.    T°     $'-°°    °N     ™E    SEVEN™     DAY 

fasten 

fix 

iru 

I  They 
^mplete 
Wftt    3    1933                                           1  place, 

air  in  either  direction. 


le  with 

f-ewith, 
hresh- 
[e  d    to 
go  on  a 
th  nei- 
thresh- 
have 
erhead 
d    corn- 
in  ad- 
pr   so  it 
[mashed 
trolley. 

,    or    all 


opened 
re   cush- 

LD  21-50m-l,'33     rush    of 

_ 


' 

; 


Complete  information,  diagrams  and  illustrations 
in  our  circulars. 


FRICK  COMPANY 


..ENGINEERS... 


Established 


Incorpo 
188: 


E( 


288 


ies 


IVERSITY  OF  CALIFORNIA  LIBRARY 


References  and  new  Ice  Machine  Circular,  describ- 
ing1 latest  improvements  ->"^  — "  .»vinR; 
Ice  arul  u.-    •,:.,.     .eratir.-                     iild<          .  fir* 
class                         STEAAl    oNUiNES,    AMMON. 
VALVES,  FLANGES,  COILS,  etc. 

CORLISS  STEAM  ENGINES 


ICE  MAKING  MACHINERY, 

STEAM  BOILERS, 
AMMONIA  FITTINGS. 


FRICK  COMPANY, 


WAYNESBORO,  FRANKLIN  COUNTY,  PA. 


